Short tours are great, but the longer missions are the ones that stick with you. Sometimes it's because they're the most fun, but other times it's because you're suffering though frozen toes for days at a time, which is memorable for all the wrong reasons. Dynafit's Winter Guide GTX Ski Boot will let you enjoy long tours and cold days in comfort, though, with a Dynafit Custom Ready liner that's outfitted with a Gore Tex Duratherm L membrane to keep your toes warm and dry when you're spending hours digging pits, sleeping at 13,000 feet, or heading out for a day of making pow turns at 15F. There's more to the Winter Guide than a warm and dry liner, though. Like any Dynafit, it can climb like a goat, with an Ultra Lock System 2. 0 skihike mode that toggles between a locked and open cuff with the flick of a single switch. When it's open, you have 60 degrees of super smooth cuff rotation for easy skinning and bootpacking, and when it's closed the Driving Spoiler 2. 0 provides bomber skiing performance. The spoiler also has an insert that lets you choose between two forward lean settings, and the cuff cinches down via Dynafit's Ultra Lock power strap, which can be loosened up with a quick pull for faster transitions. The Winter Guide also features the Buckle Cable Retention System, which folds the buckles flat against the shell when they're open to prevent snags, and Dynafit's Quick Step In tech inserts to make stepping into tech bindings a breeze, even in deeper snow.