B+W 52mm ND 0.9-8X Neutral Density Filter (103M) with Multi-Resistant Coating (MRC) 66-1066140 0.9 ND - 3 f-stops - 87.5% reduction of light - transmits 12.5% of the light from the Original scene Filter Factor = 8x Allows creative use of larger apertures for shallow Depth of field or slower shutter speeds to capture motion Blur MRC multi resistant coating - anti-reflection and easy-to-clean coating This filter uses our standard B+W F-Pro filter mount, which has a front accessory thread and is made of Brass.