For tough jobs, the WaterMaster is your answer for on-the-go hydration. The reservoir compartment and tube are insulated and the new 2. 5L, 85oz Mil Spec Crux Reservoir delivers 25% more water per sip, keeping you cool and hydrated no matter what the job site throws at you. Reflectivity and a tear-away harness give you added peace of mind and the external excess to the reservoir makes filling and cleaning fast and simple., unisex, Easy to use