The Hoya NXT Plus UV Filter is a multi-purpose filter that is most commonly used to protect the front of your lens, a first line of defense against scratches, rain, dirt and dust. Hoya's NXT Plus UV is a powerful upgrade to the best-selling NXT series. This filter applies a waterproof top coat to Schott B270 glass polished smooth for maximum sharpness. There are two advantages to having a premium waterproof coating: (1) Water beads-up quickly, and easily slides off the surface of the filter for streak-free shooting. (2) It also makes the filter a lot easier to clean when dirt, water, and smudges make their way onto the surface. Hoya applies 10 layers of patented anti-reflection (AR) HMC multi-coatings to the NXT Plus UV filter for improved contrast, color, and sharpness. The coatings deliver a 98% light transmission so you don't have to worry about contrast-killing glare. The NXT Plus filter frames are precision milled from lightweight aluminum for a slim profile that makes it perfect for all lenses including super wide-angles. What else does a UV filter do? Most photographers leave a UV filter attached to the lens all the time as a form of protection. But the filter also plays an important role in filtering through UV Haze. Haze is not a huge problem when you are taking pictures at sea-level, but as you hike into higher altitudes, the filter definitely helps cut through the haze to increase contrast and improve color. The NXT plus has a UV Cut Point of 360nm or L36 which is superior to most filters at this price point. Key Features: ? Waterproof top coat for easy cleaning ? Schott B270 clear glass ? 10-layers of HMC multi-coatings ? 98% transmission rate for sharp, clear images ? Low-profile aluminum frame