This is the game changer to your run! The 1.6 Liter Insulated Hydration bladder is low profile to reduce sloshing and it keeps your water colder for longer. No matter how hot the day is, you can be cool with this BPA free bladder with a high flow bite valve and large, easy fill opening. It's as simple as ready, set, go when you can slide your bladder into your favorite Nathan Race vest.