1 liter hydration system liquid drinking bladder

       1) Safe material. Customized is welcome.

       2) Compressive resistance to abrasion. 

       3) Tube connected to the bottom of the bladder. 

       4) Can be put into backpack and backpack's shoulder strap. 

       5) Can be used to store water with -20 to 50 degree celsius. 

       6) Foldable design, easy to carry.