Features: High-Quality MaterialThe bike trailer hitch coupler attachment made of steel with black enamel coating, made from heavy duty iron material, strong and durable, corrosion resistant, hard to damage. Universal DesignThe bike coupler attachment is suitable compatible for QR axles and solid axles up to 12.2 mm/ 0.5 inch, proper compatible for most bicycles and children trailers. Easy to UsedJust to make sure it doesn't spin while tightening, and throw an Allen wrench through the pin hole and hold in position while tightening. Portable to CarryThis sturdy bike coupler attachment is not large, you can easily carry it in your bag compatible for outdoor activities, connect your kids trailer with your bike, you can mount it on bike rear axle. Specifications: Product Qty.: 1PCSor 2PCS Optional Material: Stainless Steel +Alloy Steel Product Type: 90° Coupler Color: Black and Silver Maximum Towing Weight: About 45359g/100 pounds Applicable size: Fits QR axles and solid axles up to 12.2 mm/ 0.5 inch Package Size: 12*9*3cm / 4.72*3.54*1.18in Package Weight:111g / 3.93oz Package Listing: 1*90 Degree Bicycle Trailer Hitch Coupler 1*Safety Coupler