Bedrocker&reg; Unique Wireless Doorbell Set with Flashing LED Indicator, 1000 Feet Operating Range, 52 Optional Stereophonic Music Chimes, 4 Level Adjustable Volume Settings , Plug-in Receiver - White OPERATING RANGE: Over 900 Feet in Open Area,Wireless Range May Vary Depending on Construction and Materials. Also Remember Don't Mount the Push Button on Metal Materials. HIGH QUALITY AND EASY TO INSTALL: Remote transmitter button is excellent waterproof performance and acceptable for outdoor use. CE, FCC, RoHS certified. Easily plug receiver into an electrical outlet (no batteries required for main receiver). RING VOLUME & TONES: 4-Level of Adjustable Volume from 25db to 110db. 52 Pieces of Selectable Elegant Chimes Allow You to Change the Tune with Your Mood as Well as Set Tune to a Specific Receiver Chime. MODERN DESIGN : are the perfect doorbells that are stylish, elegant and have a modern look for any home setting. BE A MEDICAL ALARM SYSTEM: Maybe If You Have an Elderly Care Patient That Needs to Be Able to Alert from Two Rooms.