The Hoya HD Protector is the ultimate in clear filters and will not affect the colour balance or performance of your lenses. Featuring a newly developed industry leading 8-layer multi-coating which results in an average light transmission of 99.35% between 400 and 700nm (visible spectrum). Hardened optical glass that has 4 times the breaking strength will protect your valued lenses from expensive front element damage which could be caused by dirt, knocks or scratches. As with all HOYA multi-coatings HD HMC is applied in a furnace at high heat, bonding the coating to the surface of the glass. This process is called "hard coating" and it is far more durable than other coating techniques. The chemistry of the top layer is formulated not just to be more durable but to be resistant to oil stains. This means that finger prints and other oils are much easier to remove.