The Knight Vision® PVS-22 Clip-On Night Vision Weapon Sight, adds light intensification night vision to most rifles and day scopes. This product uses the latest high performance Gen 3 intensifier tube in a proven design, where the catadioptic lens provides high performance light collection with an effective f/1.2 in a light weight optic. The PVS-22 Weapon Sight is appropriate for front line rifles such as the M4 Carbine, M16A2/A4, M249, M14, and daysights with magnification up to 10x. The Knight Vision® patented technology makes the product universal and assures the accuracy of your range-tested day scope boresight will not be degraded. When the PVS-22 is added in front, your existing optic, eye relief, and cheek weld are undisturbed.