Hoya HD 37mm Protector Filter offers optimum optical performance in a clear lens filter. Manufactured in Japan, these clear glass filter does not affect colour balance, and offers the best protection for lenses, whilst maintaining optimum image quality. Features include High Density (HD) optical glass, manufactured of hardened optical glass to protect them from scratches and damage. Specialized coatings are added to the glass to make them water-proof and stain resistant. Features include chemically enhanced optical glass is 4x stronger, 8-layer Anti-Reflective Multi-Coating which greatly increase light transmission, Water and oil repellent, scratch and stain resistant, Wide-angle lens compatible ultra thin frame. Hoya HD 37mm Protector filters are suitable for lenses with filter thread of 37mm.