This Fotga brand 0.8MM PITCH GEAR for follow focus can be used with all standard prime lenses. * It is bigger than the previous Fotga gear.It is M0.8-65T,65 teeth, 0.8mm pitch,and diameter is about 49mm.It will be useful for your big lens. * It is completely compatible with Fotga DP500IIS(Can mount on the DP500IIS directly) and also fits to DP500II ((should use an adapter and longer thumb threw as the pictures shows,which are included) ) follow focus series.