Waterproof Running Vest, 5.5L Breathable Running Hydration Vest with 1.5L Water Bladder, Water Vest for Hiking, Trail Marathon Race, Ideal for Women and Mennylon mesh Imported Lightweight for Running: The 5. 5 L running hydration vest weighs just 150 g 5. 3 oz, 15. 7"*8. 2" size, reducing much of the load during the running. The less time you want to spend on the trail, the hydration backpack needs to be light. Suitable for middle and long distance running Convenient Hydration System: The running backpack comes with a 1. 5 L TPU hydration water bladder is leakproof and blowproof. The mouthpiece is