1. Optical glass, precision grinding and polishing, high-definition imaging 2. double-sided multi-layer nano-coating process, restore the true colour 3. Double-sided waterproof, oil-proof, for your lens protection 4. aviation aluminium frame material, logo engraved by laser engraving will not fade Installation will not damage the lens, change the filter at any time, do not let you miss the wonderful moment. Cautions. 1. Only UV filters can transmit 98.5 % of light; filters cannot be expressed in terms of light transmission 2. only /ND PL filters are adjustable, other filters are not. Type:C:ND8PL+ND16PL+ND32PL+ND64PL Colour:Black Material:Aluminum alloy Package Contents: 4 x Filter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.