Replacement heat treated CrMo locknuts for Mini SS 14mm axles. There are two styles, for old or new hubs.
To determine which you'll need, look at the cones on your existing hub. On the drive side of an old hub, you'll have a Chrome-Moly spacer between the locknut and the driver, where on the new style, the locknut and spacer are one piece. If your hub is more than 4 years old, you'll probably be needing the old style, which is two identical locknuts.