NiSi PRO Nano HUC UV ultra-thin filters adopt a double-sided, multi-coating lens technology that employs high quality Japanese ultraviolet absorption optical glass. It assures high transmittance and highly smooth surface that avoids unnecessary reflection. The frame is constructed from Brass using highly accurate brass milling. The NiSi PRO Nano HUC UV has an exclusive creative “U” type Nano coating and a hardened waterproof coating. The NiSI HUC UV offers a high transmittance of 99.2%.