Rear Sprocket, Freewheel, & Chain Plate Guides for the Razor MX500, MX650, RSF350, & SX500 Dirt Rocket Hyper Jammer Our Go Go scooter seat is N83 9050 Our Go Go scooter seat is the same nominal 17" width x 17" height x 14" depth seat size that is standard on all Go Go travel mobility scooters These motor brushes are internal brushes and do not require motor brush caps So if you have an earlier version of the MX500 MX650 or MX350 MX400 and ONLY need the plastic chain plate guides and or the sprocket This is a set of two chain plate guides complete with rear chain sprocket and freewheel mechanism for versions 22+ of the Razor MX500