Outdoor Products Insulated Cool Gel 2 Liter Hydration BladderRevolutionary bladder by Outdoor Products features a non-toxic cool gel insulated lining. Bladder has a quilted back evenly distributes cool gel so liquid is evenly chilled. Gel keeps liquid cold for up to 4 hours. Unlike ice cool gel chills liquid without diluting it. Fill the bladder and store in the refrigerator. Store empty bladder in the freezer, load liquid and go. Cold bladder can also be used as an icepack for small injuries. Product Details100% odorless, tasteless, BPA- Free materialRevolutionary bladder features non-toxic cool gel liningGel is evenly distributed so liquid stays cool at any levelReservoir keeps liquid cold for up to 4 hoursV-shaped body allows reservoir to easily slip into any 2L hydration bagQuick-connect hose attaches and detaches from reservoir with easeScrew-off bite valve is made from flexible silicone material. Great flow for effortless large sipsCheck out my other items!