HOYA engineers have developed a new ANTISTATIC coating that acts like a force field around the filter to repel dust. In addition, the hardened anti-static topcoat is water repellent, stain and scratch resistant, and is easy to clean if stains or fingerprints get on the surface. A Protector Filter is a popular addition to camera equipment because it protects the front element of the lens from scratches, dirt, water and other foreign objects. The filters feature a lightweight, one-piece, low-profile aluminum frame to hold the glass. This one-piece design allows the filter to maintain perfect parallel alignment to the sensor plane for maximum sharpness, while the flat shape eliminates vignetting when used with ultra-wide angle lenses.