I would guess you have the same thread and size as I do on my 228 BH; 1.2" x 20. I purchase a set of McGard 24010 Cone Seat - Under Hub Cap Wheel Locks If yours lug nuts are not under a hub, you can get the standard wheel locks from McGard.
Trailer: Lifted 228BH, heavy duty springs and Yokohama tires TV: 2016 GMC Sierra Z71 4x4 CC, SLT
Spare TV: Two Alaskan Malamutes
Living somewhere in ID; previously lived in Moab UT; previous to that, don't ask!