The UNS-LR A2 clip-on Weapon Sight (WS) is a product improved version of the AN/PVS-30 it adds the latest high performance Gen 3 light intensification night vision to most rifles and day scopes by attaching to the picatinny rail. This product is appropriate for front line long range rifles. The Knight Vision patented technology as well as the extended focus level makes the product universal easy to use from the shooting position and assures the accuracy of your range-tested day scope boresight will not be degraded. When the UNS-LR A2 is added in front, your existing optic, eye relief, and cheek weld are undisturbed. The refractive lens provides high performance light collection in a light weight design. Knight Vision patented Single Interchangeable Battery (SIB) allows use of either CR123 or AA single cells, with a battery life exceeding 24 hours while the shooter remains in shooting position. The highly efficient power circuit allows use of depleted flashlight batteries to provide several hours of operation. Single Interchangeable Battery (SIB) U.S. Patent No. 7,576,516.