Ok I don't know a whole lot about this set up, took it in trade with an Aimpoint Comp M3. Guy was using it to mount the M3 and it seemed to co-witness ok. 30mm ring is 30mm ring I guess. Anyway this includes the 17 single lever tri-lock, .50 spacer (and short screws) and the 30mm ring that is marked "Trijicon Tri-Power". Looks to be a good mount for someone on a budget. $SOLD e-mail notifications don't seem to be working so if you don't e-mail me direct it may take a bit to get back to you. Thanks!