These micro sprint axles are 52" long with 13" of spline on right side, 18-1/8" on left side, 21" smooth in the middle. Left side is standard (right hand) thread and right side is left hand thread. They are built to ISO standards. These aluminum racing axles will fit most popular micro racing chassis. Application note: This is considered the 'Short Right' axle. It is intended to fit cars that have an inboard brake and NOT a RR brake. These are also commonly used on cars with a jacobs ladder. Axle features 13" of spline on right side, 18-1/8" on left side, 21" smooth in the middle. Both ends are 1/4" un-threaded with 1/16" pin holes. Built to ISO standards. Will fit most popular chassis.