Lightweight For Running:Only the 5L race vest backpack without the water bladder, the backpack weight is 190g/6.7oz super light, reducing much of the load during the running.When it comes to running, the shorter you plan to spend on the trail, the lighter pack you'll need.Design for middle or long distance running.

Multiple Storage Compartment:Designed with 9 exterior pockets, you can store all tiny items such as vacuum cup, keys, phone and cash etc. These pockets also allow you to get the things directly, extremely convenien

Comfortable Fit Vest Pack: Fully adjustable shoulder and chest straps that guarantee the perfect fit, keeping the pack from bouncing while running. Designed with a unique padded back section to allow airflow between your back and the pack.Soft mesh on back and shoulder straps maximize breath-ability.

Fit You Well: Ergonomic designed vest-shaped bag coming with adjustable waist strap and high elastic chest strap,two sizes for your option.This backpack can be used for more than running and hiking.It is suitable for almost all outdoors activities such as running, riding, camping, marathon, etc.

Bladder Suggestion:Only the backpack included, Optional Bladder is 1.5 Liter volume not included, please noted that this link only backpack without bladder.Thanks !