Advanced knurling technology, prevent hand slip, convenient to disassembly. High quality aluminum frame designed, frame front with thread, can install lens cover and other accessory at any time. Rotating filter, outer ring can adjust the wavelength arbitrarily, from 530nm to 750nm change. Suitable for infrared photography creation, very practical integrated adjustable infrared filter, can provide you with more operable content of infrared photography creation. For internal and weak shadows, use 680nm, using 750nm indoors and in low light.