Universal Bike Trailer Hitch Coupler vs EUNORAU M12 Trailer Hitch Adapter

These are not interchangeable parts. The universal U-bolt coupler is a generic hitch that clamps to a standard rear axle on most bikes, including quick-release and nutted axles up to 12.2mm. The EUNORAU M12 adapter is a model-specific part that threads onto an M12 hub-motor axle nut on certain EUNORAU e-bikes. Buy the universal kit for a normal bicycle or a hub-motor bike with a standard axle; buy the EUNORAU part only if you own a listed EUNORAU model and its one-wheel cargo trailer.

• Choose the universal U-bolt coupler if you have a standard bike, mountain bike or e-bike with a quick-release or nutted rear axle and want a spare hitch to move a trailer between bikes.
• Choose the EUNORAU M12 adapter if you ride a listed EUNORAU hub-motor model such as the Defender, Fat-AWD, Flash or G30-Cargo and tow the EUNORAU one-wheel cargo trailer.