![Ultralight Bicycle Bag with Water Bladder Waterproof Outdoor Sport Cycling Rucksack Hydration Backpack Hiking Bike MTB Gym Pack Ultralight Bicycle Bag with Water Bladder Waterproof Outdoor Sport Cycling Rucksack Hydration Backpack Hiking Bike MTB Gym Pack](https://ae01.alicdn.com/kf/S01facaee43fe4d47b4c687285192d0c3D/Ultralight-Bicycle-Bag-with-Water-Bladder-Waterproof-Outdoor-Sport-Cycling-Rucksack-Hydration-Backpack-Hiking-Bike-MTB.jpg)
Ultralight Bicycle Bag with Water Bladder Waterproof Outdoor Sport Cycling Rucksack Hydration Backpack Hiking Bike MTB Gym Pack
![What is that little opening for on my TNF Borealis backpack? I'm able to poke my finger into the pocket when the zipper is closed. 2nd photo: what is the Velcro strap What is that little opening for on my TNF Borealis backpack? I'm able to poke my finger into the pocket when the zipper is closed. 2nd photo: what is the Velcro strap](https://i.redd.it/m7384iecd6p71.jpg)
What is that little opening for on my TNF Borealis backpack? I'm able to poke my finger into the pocket when the zipper is closed. 2nd photo: what is the Velcro strap
![Amazon.com : SEMSTY 20L Hydration Backpack with 2L Water Bladder, Insulated Hiking Backpack with Rain Cover for Hiking Cycling Camping : Sports & Outdoors Amazon.com : SEMSTY 20L Hydration Backpack with 2L Water Bladder, Insulated Hiking Backpack with Rain Cover for Hiking Cycling Camping : Sports & Outdoors](https://m.media-amazon.com/images/I/81mOAz6th8L._AC_UF1000,1000_QL80_.jpg)