B+W 52mm ND 0.6-4X Neutral Density Filter (102M) with Multi-Resistant Coating (MRC) 66-023672 0.6 ND - 2 f-stops - 75% reduction of light - transmits 25% of the light from the Original scene Filter Factor = 4x 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.