Lock Mechanism Housing
Locking ring for the standard M5/M6 locks. This will not fit solid axle nuts.
The rotatable security ring secures the coded nut against being opened forcibly. The security ring is a conical shape and leaves just enough space for your Pitlock key to fit.
Note that this is not a complete locking mechanism, only the housing. For a complete locking mechanism setup, you will also need to order a coded nut, a compression washer (either for a seat post skewer or a wheel skewer), a teflon ring, and a lock ring.