The 3590 Lock 'N' Prox is a battery powered lock with a built-in proximity reader, making it an ideal standalone solution. The RCI 3590 is easy to install and simple to program without a PC or software. The lock can be fitted to sliding doors, drawer backs, leaf doors, glass, and more. The RCI Lock 'N' Prox has an audible signal upon card/fob presentation and a low battery warning.