1、Important Parameters: C mount lens, 1in image size, 25mm focal length, 10mp pixel lens, relative aperture(D/fˊ) 1: 2、Good Image Quality: Optical coating makes your lens clearer and less prone to distortion, you need to be careful in use to avoid scratches. 3、Manual Iris Lens: C mount lens with manual focus and adjustable aperture, no lens shadow, no vignetting, high image quality. 4、Long Durability: The lens shell is made of high quality aluminum alloy, which is resistant to high temperature and durable. 5、Wide Application: C mount lens is widely used in home surveillance cameras, CCTV, TV cameras, video camera, DIY lenses, etc. 1 x C Mount Lens 1 x Adapter Item Type: C Mount LensMaterial: Aluminum alloyFocal Length: Approx. 25mm/ 0.98inFormat: 1in (Diameter 16mm/ 0.63in, 12.8x 9.6)Relative Aperture (D/fˊ): 1: 1.4Mount: C MountsField Angle: 1in, 28.9°x 21.8°2/3in, 20.1°x 15.2°1/ 1.8in, 16.5°x 12.4°1/2in, 14.5°x 10.5°Flange Back Focal Length: Approx. 17.53mm/ 0.69inAperture (Iris): Manual/Lock (W/Lock)Distortion: 0.25%Resolution: 10MPClose Up Distance: Approx. 0.25m/ 0.82ftDimension: Approx. 40.0x56mm/ 1.58x 2.2inFilter Size: M 37.5x 0.5pApplication: Surveillance camera replacement lens, DIY lens