3V Gear SERE 1.8L Dual-Tanker Hydration Reservoir - Compatible with Camelbak and Other Hydration Packs Patented articulated "Bite Me" valve with push button shut off and magnetic retention system 1.8 Liter Dual Chamber; Metallocene PE high strength & taste free film (BPA, Latex & PVC free) Tough construction for maximum abrasion resistance (2) Easy-to-use 3/4 turn 53mm (2) Fill ports; (2) Magnetic bite valve retainers