ND(Neutral Density) filter Material:Made of optical glass Sizes :37 ... ) Models:ND2,ND4,ND8,ND16,ND32 ND(Neutral Density) filter1.This products is used to reduce the ... amount of light reaching the film,to use high speed films in bright sun.but it will ... our owned factory,and specialising in producing ND filter many years,So,donot warry about the quality, ... us at any time. fader ND(Neutral Density) filter