Hyperlite Mountain Gear InsulatorHyperlite Mountain Gear Insulator The Insulator is a practical solution for staying hydrated during cold weather adventures. Built to help prevent your water from freezing, it lets you carry warm liquids in a wide mouth Nalgene bottle and keep them usable even in low temperatures. Designed with convenience in mind, it features a secure Velcro attachment that easily fastens to your packs hip belt, so your drink is always within reach while on the move.