The first thing you notice about these incredible boots, apart from how drop dead gorgeous they are, is how amazingly light they are for a fully technical B3 rated boot. The original Nepal boots were incredibly robust and long lasting, but weighed a ton, the new Nepal Cube GTX carries on the tradition of durability and reliability but at a fraction of the weight. They are made using fully insulated high quality Idro-Perwanger leather. This is a premium silicone impregnated 3.2mm rough-out leather made 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 retaining maximum breathability. This leather is the most durable available and is made from the corium, the strongest part of the leather. This high quality and incredibly robust leather is then backed by a fully insulated Gore-Tex membrane to provide the warmth needed on high altitude expeditions and the complete waterproofing needed when ploughing through wet snow. When you slip your feet into these beauties you instantly feel secured and cosseted by the internal heel and ankle padding, giving you the confidence that any suggestion of heel slip, which can be a problem with B3 boots, will be eliminated. Full ankle articulation is provided by the innovative 3D Flex System at the ankle which makes long walk-ins possible and makes these incredible boots comfortable enough for general mountaineering, despite their B3 rating. Further comfort is achieved by the EZ-OUT variable adjustable tongue; mesh covered foam is adjustable to fit and also acts as a pump to draw moisture out of the boot. The lower part of the uppers are protected from scrapes and abrasion by an air injected rubber rand, this process reduces weight and allows for a very precise and custom application; which is why these boots look so damn good. The toe area, which gets the most abuse, has a tougher material overlay. Underfoot there is a Carbon Tech honeycomb midsole which provides the strength and stability for the boot and also insulates without adding unnecessary weight. A 4mm layer of EVA foam enhances this insulation and adds shock absorbency and cushioning. To enable a secure and safe crampon attachment a 2mm Polyurethane layer runs through the midsole enabling all types of crampons to be attached. Finally a replaceable Vibram sole with aggressive lugs and La Sportiva’s brilliant Impact Brake System (IBS) provides grip and security on all terrain. IBS is a unique technology in outsole design where the lugs of the soles are oriented in opposing slanted directions. This opposition increases braking power and decreases impact forces by an average of 20%.