Banjo Brothers 03010 Small Deluxe Seat Bag is great for either for a road bike with extra gear, or mountain bike if you are carrying just the basics. This seat bag is 40 cubic Inches in size, with dimensions of 5.75-Inches long x 3.75-Inches wide x 3.25-Inches high. This bag is made of 1680 denier ballistic nylon exterior fabric that wears like iron to keep all of your valuables safe while on the trails. Both the top and bottom are padded for extra support and the gusseted sides help keep things in place when you open the bag. This deluxe Banjo Brothers bag features three interior pockets to keep tools and other sharp objects away from your tube. To keep your keys safe from dropping or getting lost, there is a key clip tether on this seat bag.