Purchase our Kid Trailer axle for your bike, and share your stoke for cycling with your kids. Simplify your life by allowing quick and secure attachment of your trailer to your best and favorite bike. Enjoy the adventure. Robert Axles for Kid Trailers are designed specifically to fit your 12mm thru-axle bike and allow attachment of any hitch-mounted trailer. These fit any trailer that has two wheels and a single point of attachment to the axle. This includes all the two-wheeled child, pet, and cargo trailers such as Thule, Chariot, Burley, Instep, Carry Freedom, and many more. - The axle shaft and axle end are precision CNC-machined. - The axle shaft is 7075 aluminum and hard black-anodized for rugged durability. - The stainless steel axle end allows for mounting of the hitch provided with your trailer. - Hardware for attachment of the hitch is included; the hitch, itself, is not. - No special tools required. Design allows for wheel installation and removal using your standard 5mm hex wrench. - Designed, built, and quality tested in the USA. Proven around the world.