3L Lumbar Reservoir 2.0A refined 3 liter reservoir for your hydration hip pack. If its time to replace or update your hydration reservoir, look no further than the freshly updated 3 Liter (100 ounce) Lumbar Reservoir 3. 0, which fits perfectly with our large mountain bike backpacks. Our tried and true Dakine x Hydrapak 3D lumbar reservoir has been further refined for easy use, starting with the improved fold and slide wide mouth opening, which makes for easier filling and