Features: 1 Made of heavy-duty steel with a welded hitch arm at an approximate 45-degree angle for ideal attachment position for many types of bicycle trailers. 2 Attaches to the bicycle rear axle with the rear axle nut. 3 Usable as a convenient and safe hitch for bicycle trailers to attach to. 4 It fits almost all bikes and all kinds of trailers. 5 With an additional trailer coupler attachment, both Mom and Dad's bikes can be outfitted to tow the kids trailer, your kids will enjoy the bike ride. Specifications: Type:Trailer Hitch Mount Material:Steel Hole diameter where axle attaches:11mm Color:Black Recessed area diameter where axle nut screws onto:21mm Hole diameter in hitch where the trailer attaches:6.8mm Base plate length:55mm Package included: 1x Trailer Hitch Mount