The air-conditioned footwear. The innovation for optimum conditions in the boot & enhanced breath-ability. The entire tongue is a combination of 3D mesh & a cushioning, reticulate, perforated sponge material that causes the pumping action. To achieve an anatomical shape, a stabiliser made from micro fleece is sewn on to the tongue. A very strong Velcro strap is integrated in the forefoot area & at the end of the tongue to secure the tongue. More ventilation, more pump-action. The technology of the Air Revolution line was further enhanced. In addition, a sock has been developed that is tailored to the function of the boot & makes the Air Revolution system perfect. The tongue now has newly defined ventilation ducts. The big ventilation perforation is on both sides & covered by mesh material. Thus, there is no impairment of ventilation or reduction of sturdiness. The waisted tongue adjusts perfectly to the shape of the foot. Also new are the reticulate, large-pored foams that are used & have a positive effect on adaptability. When your feet push off the ground, warm air is pumped out of the boot & when your feet touch the ground again, fresh air is sucked into the boot. With each step that you take, air is recycled in your boot allowing your feet to remain cool hence enabling you to carry on walking in them for longer & being comfortable all along. waterproof Air Revolution tongue design lace-loop lacing for perfect pressure distribution Meindl Mulltigriff 2-sole by Vibram with SRSystem Footwear with GORE-TEX technology is ideal for a wide range of outdoor activities. It offers a unique combination of durable waterproof protection, breath-ability & the utmost in comfort. Footwear with GORE-TEX technology enables you to enjoy your outdoor activities to the fullest, regardless of the weather conditions. All Footwear with GORE-TEX technology is manufactured according to strict quality & performance standards.VIBRAM Multilayer is a concept through which Vibram is able to offer all in 1 soles featuring: VIBRAM Multitrek compound for perfect grip, easy traction, & maximum durability TPU support to grant roll stability EVA thermo shaped midsole for increased lightness, shock absorption & comfort. By mixing all these elements into one product, VIBRAM Multilayer provides the sole with a very dynamic & rockered profile, ideal for high performance.