For M8 handlebar bolts, the RAM-B-367U motorcycle handlebar base will replace the existing bolt with a 1" B size ball. This rubber ball base provides shock and vibration damping, and is compatible with a wide variety of B size RAM® double socket arms and device holders. The RAM-B-367U motorcycle handlebar base will work with any motorcycle that features an 8mm bolt or smaller on its structure. A smaller bolt can be used, though the load capacity decreases with the bolt size.