The filter coating is not permanent. It is repeatedly damaged when wiped and weakens over time. The filter can protect the lens from physical damage, but the coating receives the blow first as a scratch. When a filter coating is solid and scratch-resistant, it will be a great advantage. This is designed with an ultra-hard nano coating to protect the camera lens. The HD nano Mk II UV filter is a filter with a UV cut-off curve that does not affect the visible light range. In addition, this filter has a new enhanced coating that protects the lens from scratches, allowing easy cleaning from water spots and fingerprints. HD nano Mk II glass is 4 times more chemically resistant optical glass. Designed to protect a camera's expensive lens system from scratches and shocks, the HD nano Mk II filter is an essential piece of equipment for photography in extremely harsh conditions.