Cenoté 2-Liter Hydration System
The new Cenoté 2-Liter Hydration System ($14, cenote.com) is the most affordable we've seen, about half the price of most other reservoirs. It's BPA-free and recyclable and has a twist-on/off bite valve just like other more expensive models. A 3-liter Cenoté system is just $1 more.