ND(Neutral Density) filter Material:Made of optical glass Sizes :37 49 52 55 ... 72 77(mm) Models:ND2,ND4,ND8,ND16,ND32 ND(Neutral Density) filter1.This products is used to reduce the amount ... .We owns our owned factory,and specialising in producing ND filter many years,So,donot warry about the quality,and our ...