The vanguard qs 40 quick release shoe has a 38 camera screw it is ideally suited for use with the tracker s tracker 1 tracker 2 tracker 3 tracker 4 tracker b 100 tracker b 200 alta 254cb alta 234ab alta 264ab mg 8 mg 8 os tripods sbh 30 sbh 50 sbh 100 sbh 200 ball heads and ph 35 ph 50 ph 55 panheads