This adaptor lets you convert any Shimano hub to fixed wheel (except Silent Clutch, 2004 Dura-Ace). When the cassette body is removed, this simply slots onto the hub and is fastened on with the same fixing bolt used for the cassette body.
The kit includes all necessary spacers to achieve optimum fit between your dropouts.
Takes locking 1.29″ x 24TPI and 10mm axle.