Specification: Focal Length-----------50mm Aperture----------------F1.8 Format------------------1/2 MOD---------------------0.3m Mount-------------------C Mount Net Weight---------------178.5g Dimension (mm) --------- ¦Õ47¡Á53 The type of 50mm Manual Iris lens is with the exact large Aperture number at F1.8, which is suitable for a low light environment surveillance. Also, the definition or said resolution is higher than other common lens, reach 0.7megapixels, which make this lens to be suitable for better video surveillance and some common industrial equipment, such as PCB Board Inspection Device as an industrial lens. Similar product: 25mm F1.8 1/2" Manual Iris C Mount Lens.