Outdoor enthusiasts know the importance of staying hydrated. When the temperatures vary, that makes it a little harder. This Osprey Packs Four-Seasons Hydration Insulation Kit is designed to keep your water reserves ready. Lightweight and easy to carry, its reservoirs can hold 3 liters of water. This innovative kit reflects hit and has a foam sleeve for ultimate insulation. The hose is insulated to keep the sun's rays at bay. The mouthpiece features a zippered bite valve sleeve to keep ice at bay in cold weather and is removable for warmer weather use.