Camelbak Crux thermal Control Kit is designed to stop the tube & bite valve on your Camelbak from freezing in cold weather. This is useful for winter mountain biking & also if you want to take your mountain bike Camelbak skiing, snowboarding or mountaineering. The new crux thermal control kit takes insulation to the next level so your tube & valve stay ice-free. Designed for reservoirs with the quick link system, this cold-weather accessory will extend the range of use your hydration pack during all outdoor adventures. Features • insulated tube: protects the flow of your fluids in cold conditions • freeze-proof valve: integrated cover keeps ice from forming in bite valve • fits reservoirs with quick link system: keep your crux working very hard year-round with this easy upgrade