Simply the best hydration system we have tested and used; this water reservoir is leak free, taste free, BPA free. Comes in 2 liter (70 oz) and 3 liter (100 oz) sizes, and turns your biking or hiking backpack into a mobile, sippable water source so you don't have to stop during a workout to hydrate. The inner-surface is self-cleaning and stays free of gunk. Learn more about the 2.0-liter reservoir here: http://www.tahoemountainsports.com/pr... Learn more about the 3.0-liter reservoir here: http://www.tahoemountainsports.com/pr... Purchase a replacement bite valve here: http://www.tahoemountainsports.com/pr... Get a Streamer Insulator Cover here: http://www.tahoemountainsports.com/pr...