High image-quality monitoring with optical performance supporting 3 megapixels. Advanced design engineering and special optic glass adopted, best suited for color, black and white, and day and night cameras. SLA-F-M1550DN has an f15-50mm, 3.3x zooming application compatible lens. This lens is designed to maximize optical performance with high-accuracy aspheric lens, low-dispersion glass, and high refractive-index glass. Built-in ND filter of T360, supporting high sensitivity cameras.