When you want to be light on your feet for a quick trail run after work, turn to the Ultimate Direction Mountain 4. 0 Hydration Belt. Carrying enough hydration for all-day adventures in a small bounce-free format, the Mountain 4. 0 employs a MonoRip mesh dual compression waist belt for a secure and breathable fit, along with a rear PowerStretch woven mesh pouch to comfortably hold a 600mL FlexForm Plus water bottle. The zippered pocket safely carries your smartphone, while the front strap offers a secure spot for your house or car key.