Honeywell RCWL300A1006 Premium Portable Wireless Doorbell / Door Chime and Push Button Wireless and operates on 3 LR6 AA alkaline batteries Works with up to 3 push buttons, motion detectors, or door contacts for added security and convenience Has three chime tunes, fully adjustable volume, and 3 visual alert icons Self-learning code system automatically adjusts to eliminate interference Features a 250-foot operating range