Water is life. You need to have a hydration system of some type for range training, emergencies, travel or recreation. Camelbak has stayed at the forefront of hydration systems and is the one many other companies copy. Their packs are easy to use, clean out and are comfortable to wear all day on the range, biking or hiking. I keep one non-tactical-looking example stuffed with gear for covert emergency use. I have several others set up for various uses. Select at least one that fits your needs. Reservoir features: more than just a reservoir, the MIL spec antidote reservoir redefines the ultimate delivery system for an Operator's water supply and provides maximum adaptability for changing missions or combat environments. Includes our quick link exit Port and ql hydrolock Bite valve adapter: tube clicks off for faster refilling with auto shut-off; new fill Port: industry's largest opening with air-light 1/4 turn open/close for quick, secure seal that can't be over-tightened; lighter weight lower profile design. Additional features: external fill access-allows for a quick Refill without removing pack, Side-Release shoulder straps for rapid removal, multiple drink tube exit ports-for routing drink tube over the shoulder or under an arm, noiseless zipper pulls, top and bottom external zip pockets hold your essentials, lightweight, durable 500D corduroy fabric.