Adjustable shoulder, chest, and waist straps to ensure a stable and suitable carry for a perfect fit.There is a hidden mesh bag to cover your helmet while you are cycling.And you can take your water bladder(not included).This pack is made of sturdy rip-stop scratch resistant Nylon Material. Great zippers – durable zipper, well-sewn craftsmanship, high dense stitching. Built with strong stitching in the places you need it such like the shoulder straps, carrying handle, bottom and other places. With waterproof rain cover prevents your outdoor gear from getting wet in drizzle.