With the Thule(R) Shimano E-Thru Axle Adapter, attaching your Thule(R) child carrier to your bike with be quick and easy. This E-Thru Axel adapter is easy to install and fits bikes with 12 mm Shimano E-Thru rear axle. Take your child for a ride on your favorite paths. FEATURES: E-Thru Axel adapter Designed to be used with Thule(R) Child Carriers Fits bikes with 12 mm Shimano E-Thru rear axle