This is a hydraption pack,which can use for outdoor sports,like running,cycling,hiking,camping,climbing and daily training. 1.The fabric is nylon ripstop with PU coating and light waterproof function.The fabric color is very bright,suitable for both male and female. 2.Size is W24*L8*H41cm 3.screen printing on the front part 4.external expandable stash zone with 2pcs durable buckles for towel,helmet,clothes etc 5.main pockets with #5 double-way zipper,you can put 1.0~2.0L bladder by velcro adjusted straps. 6.two side net pockets for bottles 7.mesh shoulder padding and back for breathable 8.two sides can be used suitable for both left and right handers 9.special zipper puller 10.chest straps with buckles can be adjusted to make confortable 11.inside silk binding to be strong 12.handle straps for easy carry