The Altitude GTX Boots deliver all day comfort and breathability even with the occasional heavy load. They come standard with the Crispi Crossbow Frame – a special insert that functions similar to a crossbow and significantly reduces shock and enhances stability. Stability is further enhanced thanks to the Crispi Thermo Wire Technology which utilizes extra structure and also provides more support to the shoe. The Board Lasting Mechanical Construction achieves the perfect connection between torsion rigidity and flexibility thanks to a mechanical process that wraps the comfortable and soft part of the upper to the insole frame. Additionally, the Altitude GTX is equipped with Gore Tex waterproofing to keep your feet dry in any condition. Features of the Altitude GTX Boots: Crispi Crossbow FrameBoard Lasting Mechanical Construction Crispi Thermo Wire TechnologyVibram Megagrip OutsoleGore Tex Waterproofing Crispi Women's Altitude GTX Non-Insulated Anthracite Boots 1425-6600