Description: Double Sided Multi Layer Optical Coating: effectively reduce the reflection on the surface of the filter, reduce and phenomenon caused by the reflection of external light for long term exposure, and ensure good image quality Waterproof : The surface of this filter is delicate and smooth, such as water droplets falling on the mirror surface, leaving no marks, and easy to clean, which is loved by photographers Anti Oil: The anti oil coating layer makes the surface of the lens smooth, not easy to be stained, effectively protects the lens, and is suitable for photographers with peace of mind in harsh environments. Optical glass and high definition: using transparent optical glass and coating technology to weaken the local exposure. Slim Frame:Adopt aviation aluminum alloy frame, only 3.15mm. Specification: Material: optical glass aluminum alloy Frame thickness: about 3.15mm Number of coating layers: double sided 18 layer coating Package Includes: 1 Piece Black Mist Diffusion 1/4 Lens Filter Note: Please allow slightly errors due to manual measurement and different monitors.