This is a 1.8mm focal length camera lens; It has a large F2.4 aperture. High-definition image, good color reduction, and low distortion. It allows more of the scene to be included in the photograph and works well during the day. It is easy to install and remove without affecting the installation and use of other accessories. Specifications: Product Name: Camera Lens Color: Black Material: Glass and Metal Model: CW-BL1820-IR Focal Length: 1.8mm Relative Aperture (D/f'): 2.0 Interface (Mount): M12 Image Size (Aspect Ratio): 1/3 Field Field of View (Field): 170 Pixel (MP): 1MP Back Focal Length: 4.9 Package Contents: 2pcs x Camera Lens About chromatic aberration: The goods sold are all taken in kind, but due to different lighting, monitors, etc., there will be a little color difference, which is a normal phenomenon, not a quality problem! About size: The dimensions of the products sold are all manually measured. Due to different measurement methods and tools, there may be an error of 1-2mm, which is normal!becomeveryrich