Features 1、The bike trailer hitch coupler attachment made of steel with black enamel coating, made from heavy duty iron material, strong and High quality, corrosion resistant, hard to damage. 2、The bike coupler attachment is suitable for QR axles and solid axles up to 12.2 mm/ 0.5 inch, proper for most bicycles and children trailers. 3、Just to make sure it doesn/u0027t spin while tightening, and throw an Allen wrench through the pin hole and hold in position while tightening. 4、This sturdy bike coupler attachment is not large, you can easily carry it in your bag for outdoor activities, connect your kids trailer with your bike, you can mount it on bike rear axle. Specification Features: 【High-Quality Material】The bike trailer hitch coupler attachment made of steel with black enamel coating, made from heavy duty iron material, strong and High quality, corrosion resistant, hard to damage. 【Universal Design】The bike coupler attachment is suitable for QR axles and solid axles up to 12.2 mm/ 0.5 inch, proper for most bicycles and children trailers. 【Easy to Used】Just 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 Carry】This sturdy bike coupler attachment is not large, you can easily carry it in your bag 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: 222g / 7.86oz Package Listing: 2*90 Degree Bicycle Trailer Hitch Coupler 2*Safety Coupler Package List ing: 2*90 Degree Bicycle Trailer Hitch Coupler 2*Safety Coupler