Glossary of Terms

3D Flex — A hinge system used in the ankle area of boots to allow lateral flexibility while still allowing longitudinal lockout for excellent support.

AirMesh — Nylon fabric woven into a breathable mesh pattern that is extremely durable.

Aluminium — Allergy-proof and non-toxic insulating material made of synthetic fibers combined with aluminium. This enables enhanced foot protection by reflecting infrared rays towards the heat source. It increases up to 100% the thermal efficiency in comparison to the best paddings on the market.

Anfibio Leather (2.5-2.8 mm) — Extremely water repellent full-grain leather with the grain layer, or top-grain, facing out. A special tanning process is used for optimal water resistance.

Aramide — Aramids are a family of nylons, including Nomex and Kevlar. Kevlar is used to make things like bullet proof vests and puncture resistant bicycle tires.

Board Lasted — The method of crafting shoes around the insole (also called the board). In board lasting the insole is fixed to the last/form and then the upper of the shoe is wrapped around this assembly. In the final step the midsole, rands and finally the outsole are attached to the shoe.

Compression Molded EVA — Cushioning technology and material used in most modern day running shoes.  EVA stands for Ethyl Vinyl Acetate.

Cordura® — Durable woven Cordura nylon is flexible and extremely vapor permeable.

Dacromet — Exclusive La Sportiva anti-corrosion coating. Keeps moisture and chemicals from degrading the integrity of our tempered steel shanks.

Dentex — Our top-secret proprietary synthetic rock shoe lining material with two way stretch.

Dot Rubber Sole — This sticky climbing rubber sole features a "suction cup" dot pattern for climbing shoe performance on rock and hiking sole traction on the trail. The concave suction-cup tread design provides superior traction in all types of snow, where solid dot-rubber patterns are extremely slippery and very scary.

Dry-Best® — A patented multi-zone lining system that transports moisture away from the skin via an exclusive underlayer of 100% Hydrofil nylon from Honeywell, Inc. The fabric layer closest to the skin is always dry, cool and comfortable.

Dynamic — A Schoeller® fabric made of Cordura, Lycra and plyamide. It is permanently elastic, hard wearing and breathable.

E.S.P. — Our "Edging Stabilization Platform" system combines a Thermoplastic Urethane (TPU) arch reinforcement insert with a full length polypropylene shank that is die cut and molded into the MEMlex midsole. The E.S.P. provides lightweight torsional midsole stability for trail running and a functional edging platform for rock climbing performance. The system is extremely lightweight and remains flexible at low temperatures.

EZ Fit — Adjustable padded tongue secured with hook and loop which can be moved up or down in the boot to adjust internal volume in the instep of the boot for a precise fit.

EZ Flex — Removable articulated and hinged tongue design that effectively eliminates binding in the instep area of our mountaineering boots. Adjustment system helps facilitate a perfect fit for different foot shapes.

EZ Flex2 — Same articulated and hinged tongue system as the EZ Flex without the removable feature and the adjustment system.

EZ Out — A nylon loop secured to the tongue bellows that allows simple and quick release of the locking D-rings in the EZ Roller lace system.

EZ Roller — Our Mountaineering boot lacing system incorporating steel roller ball eyelets and locking D-rings for effortless and precise tensioning of boot laces.

FCS — Flex Control System.  A technology that positions flex friendly materials in optimal positions and aligns them in orientation with the key flex zones of the midsole and outsole. 

FlyTec II — A two-way stretch synthetic woven fabric that is extremely durable and weather resistant yet soft and flexible.

FriXion® — Our proprietary sticky climbing rubber formula that can be injection molded to make lugged outsoles or die cut from extruded sheets.

Gore PSC Construction — A new Gore-Tex® footwear construction method that bonds the Gore-Tex® membrane to the bottom of the shoe to form a waterproof barrier. Differs from the traditional method where the Gore-Tex® membrane is sewn into a bootie.

Gore-Tex® — A waterproof, breathable membrane. The Gore-Tex® tag on our boots indicates a rigidly tested seam-taped sock or PSC construction which meets Gore's highest standards and is backed by Gore's waterproof guarantee.  There are three types of Gore linings:  Insulated Comfort Footwear, Extended Comfort Footwear and Performance Comfort Footwear.

HP3 — Our new polymer midsole material. HP3 is stiff durable and remains unaffected by extremes in temperature. (see Hytrel).

Hytrel — A space-age nylon product from Dupont used in our midsoles and insoles.

Ibi-Thermo — A fibrous synthetic midsole material with superb insulating properties. Ibi-Thermo will not conduct cold up from the ground and locks in the natural heat produced by the feet.

Idro-Perwanger Leather (2.6-3.2+ mm) — This premium silicone impregnated rough-out leather is made for us by Perwanger Leather of Italy. Perwanger has been making leather in the Southern Tyrol region of Italy since 1780 and tans their Idro-Perwanger hides with a special process to make them extremely water repellent while still remaining breathable. This leather is the most durable available and is made from the corium, the strongest part of the leather.

Impact Brake System (I.B.S.) — A proprietary technology in outsole design where the lugs of the soles are oriented in opposing slanted directions.  This opposition increases braking power by an average of 20% and decreases impact forces by and average of 20%.

Insole — A layer of material shaped to the bottom of the last and sandwiched between the outsole/midsole and the foot inside the shoe. It is the structural anchor to which the shoe's upper is attached. In most of our boots it provides the torsional and lateral rigidity and determines the shoe's heel-to-toe flex motion.

Keprotec® — Developed by Schoeller® it is a high tech fabric that is extremely abrasion and tear resistant.  The components are Cordura®, Dynafil TS-70, Kevlar® and polyurethane. An impregnated finish is impermeable to water, oil, and dirt.

Kevlar® — An aramid fiber used as a vital component in making durable, light weight fabrics for use in performance hiking and trekking footwear.

LaSpEVA — A soft yet fast rebounding EVA material that is extremely resilient and comfortable.

Laspoflex — Super lightweight, ultra-thin synthetic fiber-laminate designed for maximum torsion rigidity.

Last — Also called a form or forma, it is the mold of a human foot (from just above the ankle down) around which a shoe is built. The last determines how a shoe fits; whether high volume, narrow, wide, for women's feet, or men's feet. A well-designed last is necessary for a good fitting boot and truly reflects the art of shoemaking.

Lavaredo Sole — A Vibram® sole designed for alpinism.  Equipped with aggressive lugs and a flat edging platform underneath the big toe and instep.

Lock Harness® — A technology used in climbing shoes to create a support system which wraps the foot and offers a more secure fit while heel hooking.

Lorica — A synthetic leather that is constructed from extremely small micro-fibers for a water-repellant, breathable and highly durable material.

MEMlex — A compression molded midsole of 80% EVA and 20% SBR that provides a firm, cushioned midsole that is very lightweight.

Micropore — A microcellular rubber with a closed cellular pattern used as a midsole material for shock and energy absorption. Extremely dense and lightweight, it is highly durable and will not absorb water.

Midsole — The layer of soling between outsole and insole. Used on some outdoor boots to provide a layer of cushioning and on rock shoes to provide torsion rigidity and edging capability.

Montagna Sole — The original Vibram® sole designed for use in hiking and mountaineering footwear.

MPE Sole — MPE stands for Mountaineering Performance Evolution. Made by Skywalk, this proprietary sole features a dual-density SBR design, an SBR Aircushion, self-cleaning lugs, and automatic crampon compatibility.

Mtnflex Insole — A tapered Hytrel nylon insole with a full-length, Dacromet coated and tempered steel shank. All La Sportiva insoles are proportionally graded to fit the sizing structure of the boot and to create the perfect flex for different size feet. A size 42 Mtnflex insole is tapered from 7-8 mm with a 1.5 mm or 2 mm Dacromet coated tempered full steel shank imbedded. Lhotse Mtnflex insoles also contain carbon fiber reinforcing for added torsional rigidity.

Mulaz Sole — A Vibram® sole designed for technical alpinism.  The sole is equipped with a climbing zone platform under the toes and the instep.  The lugs are aggressively shaped for ultimate traction on varying surfaces.

Nubuck Leather (2.6-2.9 mm) — Very supple and full-grain, the top-grain is micro-abraded for a soft finish of close fibered and water resisting leather. Because the grain layer is sanded, this leather accepts water repellent formulas very easily.

P3® — Permanent Power Platform used in climbing shoes to maintain the downturned shape of the shoe for the life of the shoe. 

Pacific — Synthetic fiber lining material with characteristics of dynamic adaptibilty (it stretches).

PE — Polyethylene is vinyl polymer, made from the monomer ethylene. It is the most popular plastic in the world.

Powerhinge — A technology used in climbing shoes where the bottom of the outsole has a hole cut in it.  The slingshot rand is then engineered to connect to the sole of the shoe in this area.  When the toe of the shoe is weighted on an edge the weight of the climber stretches from the heel forward.  The hole cut in the sole causes the shoe to only stretch in the back half of the shoe effectively leaving the toes in place on the surface of the rock.

PU — Polyurethane is a polymer elastomer. When compression molded it is an excellent footwear midsole component because of its lightweight, durability and ability to absorb impacts.

PU Aircushion — Found in polyurethane outsoles, this shock absorbing midsole is the inner hidden component of this dual density system. The foot and insole ride on this softer polyurethane aircushion that is molded in one piece to the harder lugged rubber outsole.

Primaloft® — Synthetic microfiber insulation which uses ultra-fine and multi-diameter fibers in a specially engineered process that works with the structure of the boot to help keep feet warm and dry. Together the fibers form a torsionally strong, resilient, breathable and water resistant insulating core.

Rand — The area above the sole of the shoe around the toes and midfoot.

RockShock — A lightweight soft EVA compound that provides maximum heel and forefoot shock absorption. The RockShock/MEMlex combination forms the dual density midsole unit.

RFS — Reactive Flex System.  An ankle support technology that incorporates elastic materials that are shaped in a specific pattern to promote a fast return and recovery to the upright position of the ankle during a stride.

SBR Aircushion — State of the art modern one-piece synthetic butadiene rubber outsoles incorporate both an outer sole visible to the eye and an inner integral midsole, which provides shock absorption. A honeycomb heel grid flexes upon impact and a softer density rubber forms a midsole cushion from heel to toe while the dense rubber outsole remains abrasion resistant for long wear.

Sensi-Flex — A 2mm proprietary midsole stiffener used in rock shoes that provides exceptional support and a smooth flex while still allowing optimal sensitivity.

Slingshot Rand — Internationally patented by La Sportiva, this one-piece rubber rand wraps around the entire foot preventing stretch and driving the foot forward for a powerful forefoot fit.

Slip Lasted — The method of footwear construction in which the upper is sewn into a sock and then slipped onto the last. Slip lasted shoes normally do not have an insole and get their "stiffness" from the midsole which is located just above the outsole. Slip lasted rock climbing shoes tend to be sensitive like the Mythos and Cobra and less stiff than board lasted shoes.

Spylon — A synthetic nylon fabric that is extremely wear resistant and breathable.

SST — A lightweight "Slingshot Stabilization Technology" harness, modeled after climbing shoe slingshot rands, integrated into the upper and biomechanically positioned to maximize rear foot stability. The slingshot keeps your heel locked into the heel-cup of the shoe.

Strobel Construction — Slip lasting where the upper is stitched to a light flexible insole often made of a canvas like material using a "strobel" stitch.

SuperTrek — New rubber compound by Vibram. It is sticky like rock shoe rubber but more durable. Used primarily in hybrid rock shoe/mountaineering footwear.

Synergy Liner — A triple laminate lining consisting of a waterproof/breathable membrane, next to a layer of 200 gram Thinsulate®, and lined with a hydrophobic three-bar-knit. This high-tech sandwich from 3M® retains heat and lets out moisture, all in a super-light package without adding sensitivity robbing bulk.

Thinsulate® — A lightweight, highly durable synthetic insulating material made by the 3M® corporation.

Three Bar Knit — A synthetic material with superb wicking properties often used as a protective and hydrophobic layer in conjunction with Gore-Tex® or Thinsulate® boot inners.

TPU —Known as Thermoplastic Urethane, TPU can be fine tuned to create the perfect material for the required end use.  It is highly abrasion resistant and it is exceptionally strong in cold temperatures.  The scrap can also be easily reprocessed.

Trailflex Insole — The Trailflex insole consists of an advanced Hytrel compound surrounding a 1 mm tempered steel shank. Like the Mtnflex, it is proportionally graded to fit the sizing structure of the boot to create the perfect flex for different size feet. A size 42 Trailflex insole is tapered from 4-5 mm with a 1 mm Dacromet coated tempered half steel shank imbedded.

Trailon — A compression molded midsole of 70% EVA and 30% IIR (Isobutylene Isoprene Rubber) that provides a firm, cushioned midsole that is very lightweight. Known for its high tensile strength the IIR is mixed and injection molded with the EVA to provide extra longevity and abrasion resistance.

Trail Shock — A lightweight high cushion EVA compound that is used in dual and triple density midsoles to provide exceptional cushioning.

Trangoflex — A lightweight synthetic insole stiffener that provides an exceptionally smooth flex pattern and the ideal stiffness for semi-automatic crampons.

Upper — All parts or sections above the shoe's sole that are stitched or otherwise joined together to become a unit, and then attached to the insole and outsole.

Uretech — A mixture of sand, rubber and glue that is sprayed or painted on shoes to provide a lightweight, abrasion resistant coating that is flexible and highly moldable.

Vibram® — The most trusted name in the boot sole business. Makers of the Montagna sole and XS Grip rubber.

XS Grip — The hardest and stickiest climbing rubber on the market made for La Sportiva by Vibram®. XS Grip comes in a number of different thickness' including 3.5 mm, 4 mm, and 5 mm. This proprietary formula surpasses all others in edging ability and smearing performance while remaining durable and even wearing.

XS Edge — The best possible rubber formula for technical edging.  XS Edge was developed specifically for La Sportiva and the production of the TC Pro climbing shoe. This rubber compound is exceptionally resistant to deformation on razor sharp edges and it will not creep when smearing.