The Con-Tec MILE GRINDER EXTRA is a small but spacious saddlebag that can tools, patches and a spare inner tube.There's also a stretchy mesh bag attached to the back that can hold a drink bottle or rain jacket. The saddle bag is divided into a large main compartment and two small side compartments where you can also put your house keys or handkerchiefs. It comes with a rain cover and the bag is also waterproof. The "Mile Grinder Extra Saddle Bag" attaches to your bike's seatpost with Velcro straps - where it won't leave any scratches.