Mazama's Trailflow Reservoirs are an unrivaled rugged and reliable replacement bladder compatible with most hydration packs. Our thoughtful design ensures hassle-free refilling and pack loading. Fill-up is quick and easy through the large port (63mm for 2L and 80mm for 3L) and the half-turn, water-tight screw cap will keep your pack bone dry. Best of all, the large port makes cleaning and drying a breeze. The quick connect exit port lets you leave the drink tube on the pack when the reservoir is detached for filling, chilling in the fridge, or cleaning. The Trailflow's high-flow (5/16” ID) drink tube and GYZR bite valve provide more water per sip and the option for streaming flow. Most importantly, our BPA-free, PVC-free, phthalate-free materials leave your water tasting like a clear mountain spring, not chemicals and plastic. Trailflow reservoirs also have a convenient hang loop on both ends. We're confident you'll find our Trailflow reservoirs to be the ideal hydration solution whether you're camping, hiking, biking, skiing, running or Bigfoot hunting!