Item Type: Filter Brand: FOTGA Material: Aluminum Alloy + Optical Glass Color: Red Frame Thickness: Approx. 1 cm/ 0.39 inch Caliber: Approx. 58 mm/ 2.28 inch Main Function: Reduce the exposure by reducing the brightness of the lens Weight: Approx. 64.5 g Package List 1 x Filter 1Adopts mature optical glass refining technology and strict optical cold processing process, ensure ND mirror performs well in sharpness. 2The biggest technical difficulty of ND filter is to control "color deviation". This ND lens has no effect on color balance and light contrast of shooting objects. 3Adopts pure optical glass, the core of a filter is its optical properties. Optical glass has stable optical properties and high optical uniformity. Adopts pure optical glass and completes each optical cold processing process in strict accordance with production process requirements. 4The frame is made of high quality aluminum alloy, and the adjustable filter can be transferred from ND2 to ND400 to meet your requirements of different exposure, solve the tedious photography and bring you better experience and convenience. 5The main effect is to increase exposure time and exchange for a big circle of light, which can effectively slow down the shutter speed.