The Thule Thru Axle Shimano Adapter replaces the 12 mm rear axle on your bike. This allows you to attach a Thule ezHitch so you can tow a Thule child carrier or multisport trailer. It works with the Thule Cheetah, Cadence, Chariot or Coaster trailers and is simple and easy to install. It is 12 mm in diameter and for use with 172 mm or 178 mm length Shimano rear axles with a M12 x 1.5 mmthread pitch.