DocI do a fair bit of cycling and was looking to replace my cheap bag. I found this one by chance, when I lifted the bag I was instantly stunned by the quality. It has a pocket for placing a hydration bag which is foil lined to stay cool against the riders back, it also has a hook to hang the water pouch. It has a 3 tier sytem, large pocket for hydration pouch and bike pump (other stuff which you can stuff in there), medium pocket for random stuff (I use this for tools), and small pocket with other various pouches (use this for my wallet keys and phone). The base bag has a zip which contains mesh which can be stretched over the bag, this is used for holding a helmet. (very handy) The waist restraints can be rolled up and placed inside the pack, held in place by Velcro. It has a chest strap also. The main straps have plastic brackets for holding the straw of the water pouch. The bag also has a zip around the side and base allowing the bag to be expanded. The zips all work grand, the bag appears to be water proof and is very comfortable. One issue remains, the bag is surprisingly heavy for the size. This could be due to build quality, however some cyclists would find this a draw back. Overall the bag is comfortable, looks great and is of high quality. I would recommend this item to others. (I'm surprised to find this back so cheap) Well done Trespass!