Zefal Outdoors Hydration Bag 1.5 Liters - Stay hydrated while enjoying the outdoors. Constructed to be durable and comfortable all day. There is 1 large main compartment with an external zipper and a separate hydration bladder sleeve, which allow you to easily carry extra food, tools, or other critical items to make sure that you have all that you need for your journey. The pack also has an external mesh pocket with a reflective trim to conveniently hold your energy bag or a cell phone. Housed inside is a 1.5-liter hydration bladder made of BPA free PEVA material insuring a clean and pure taste.