When Klim built the industry-first Adrenaline GTX® Boot, it set the standard for technical snowmobile footwear. For the Adrenaline’s 3rd generation, perfecting & improving upon a near-perfect formula was our goal. Adrenaline provides a dry, comfortable, & supportive riding experience across a wide range of conditions without impeding freedom of movement. Features guaranteed to keep you dry® gore-tex® technology 600 grams of 3m™ thinsulate™ insulation insulation inside gore-tex® membrane ensuring a dry thermal layer extremely durable/aggressive sole moisture-wicking liner plush liner materials speed lace system comfortable yet stiff/durable sole internal cushioning lower ""d"" ring position to hold cuff down removable moisture-wicking ortholite® insole ankle cutout promotes forward flex use of a technical sock is required to ensure gore-tex® footwear top performance replacement laces available half size fit created with included insole insert