When you require a lightweight, precise, powerful boot for your next ski mountaineering adventure, look no further than the Sideral Alpine Touring Boot from La Sportiva. The Sideral is made with a Grilamid shell that is extremely lightweight. To help maintain the lightness but improve power and skiability, La Sportiva added carbon fiber reinforcements throughout the shell of the boot. Since long days in boots tend to be the norm in the mountains, a thermo moldable Palau liner mitigates any chafing or hot spots before they become a problem. To keep your feet from freezing during alternating belay pitches, La Sportiva put in a removable WarmSole insert that prevents the loss of heat through the bottom of the boot. When speed matters, you'll appreciate the ease of the Fast Lock System and the QuickBuckle upper that allows you to switch from ski to walk mode with the flick of a switch. When in walk mode, these boots provide a hefty 68 degree cuff rotation, perfect for sections of more technical climbing. A LazerGrip Outsole with dual density rubber positions climbing rubber where you need it for grip, and softer, shock absorbing rubber under your heel and ball of your foot to allow you to go for longer.