Bike Trailer Coupler Hitch Bicycle Attachment Includes Washer Plate Locking Pin Fits for models for most Schwinn and Instep trailer that accommodate 2 children to a bike. (Manufactured before Oct 25, Series AF, AA, AB, AC, AD, AE) Locks in place securely and does not swing back and forth when attached to the bike. 5-10 mins installation; once installed, take only a few second to attach or remove a trailer. Black coating made it blends into your bike perfectly even when no trailer is connected. Includes with lock washer, coupler plate, and locking pin.