At 135 cubic inches, the Seat Bag is a great “catch all”. Fitting your cell phone, wallet, keys, bike tools and even a water bottle this simple to use bag will hold any odd and ends you want to take with you. As an added option it can hold a water bladder up to 1.5L. The bag slips over the back or bottom of the seat and can easily be removed and carried by the handle on the top. It provides excellent use of free space and will not interfere with the Head Rest, Rear Rack, trunk pack, or panniers.