ULTRA THIN multi-layer Pol.Circ filter that reduces the risk of vignetting. The EVERCLEAR 5 coating makes a point of its name. The 5 stands for the five advantages of this coating: water repellent, oil repellent, dust repellent, dirt repellent and scratch resistant. An ultra-thin design results in a very low weight. Light rays reflected from any surface can be polarized, so polarizing filters are used to select which light rays enter your camera lens. CIR-PL filters allow you to remove unwanted reflections from non-metallic surfaces such as water, glass, etc.