1、Important Parameters: This lens works with CS mount, with 23 degrees horizontal feld of view, 1/2in lens optical format, and 30 x 34mm/18 x 34in dimension diameter. 2、Tough Shell: The lens is covered by high quality aluminum alloy shell, which resistant to high temperature, and better protect the delicate lens. 3、Highly Accurate: The easy to grip focus ring provides precise focus for highly accurate shooting, ensures sharp image with low distortion. 4、Adjustable Aperture: This lens allows you to adjust aperture of the lens in response to the light levels it affects parameters in the imaging system. 5、Easy Installation: You just need to screw and fix the aperture lens into the back focus adjustment ring on your HD camera. 1 x Lens Item Type: Fixed Focal LensMaterial: Aluminium AlloyModel No: CW-FM1614-3MPFocal Length: Approx. 16mm/ 0.63inOptical Format: 1/2inD/f': 1.2Mount: CS mountField of View: 23 degree (H)Back Focal Length: Approx. 7.53mm/ 0.30inIris: Manual lockMTF: 3Mega PixelMOD: Approx. 0.2m/ 7.97inDimension: Φ 30 x 34.00mm/ 1.18 x  1.34in