Wireless Doorbell, AVANTEK DT61 Waterproof Door Bell Chime Kit, 48 Melodies, 650ft / 200m Range [1 Push Button & 1 Plug-in Door Chime, Black] Includes 1 battery operated transmitter and 1 plug-in receiver; features 48 classic chimes with 4 adjustable volume levels; sleek design easily blends with the decor of your home or office Up to 650ft / 200m working range, great for your apartment as well as your commercial space, also practical to care for the elderly or immobile patients as a paging alert device Receiver can be plugged into any standard outlets in your home or office; IP44 rated waterproof transmitter can be easily installed to the wall with provided screws or double-sided adhesive tapes Blue LED flashes when someone is at the door; a specially designed coding system helps prevent interference from other users or appliances; super-efficient eco power management mode reduces power consumption FCC, CE, and RoHS certified