This transaxle assembly kit includes the transaxle, two (2) axle keys, and two (2) mounting bolts for the motor. The kit does not include the mounting brackets or screws required to mount the transaxle to the frame of your scooter.
Unfortunately with this being a special order item, we do not have one here to get the measurements on the diameter of the keyed shafts nor has Invacare been able to provide that information. We do know this trans axle assembly is exclusive to the Invacare Lynx L-3X only. We do apologize for any inconvenience.