Pitlock Replacement M5 Coded Nut
This is an M5 coded nut, which can be used as a replacement for your existing Pitlock locking mechanism. This is intended for quick release skewers, and will not fit solid axles.
Note that this is not a complete locking mechanism, only the coded nut. For a complete locking mechanism setup, you will also need to order the lock housing, a compression washer (either for a seat post skewer or a wheel skewer), a teflon ring and a lock ring.