Billet aluminum drive coupler for the Kawasaki 12F, 15F, Ultra 150, and the SX-R 4-stroke. 24-1.5mm threads. Can be used with the ADA Racing 27-1.5mm HD coupler (part# 34-7004) on Yamaha and custom applications. The total length is 2.065". ADA Racing recommends running these in sets. This is for 1 single coupler.