SIMPLE SETUP: Just plug the mini receiver into a socket and fix the transmitter on a wall with the accessories provided; includes 2 screws, 2 anchors, a key and a piece of double-sided bonding tape 300 M/1000 FT ULTRA LONG WIRELESS RANGE: 1 plug-in receiver included; will not interfere with other equipment in your home or those of your neighbors; ensures you will never miss a visitor, even if you are a few rooms away or on another floor 52 CHIMES TO CHOOSE FROM: 1.1 in (29 mm) stereo speaker delivers rich and crisp sound; 5 adjustable volume levels with a maximum setting of 115 dB; press Next or Previous button to easily choose from 52 melodies HIGH PERFORMANCE TRANSMITTER: Ultra-low power consumption; uses a lithium battery that boasts 3-year maximum lifespan; IP55 dustproof and waterproof rating; works between -4 F to 140 F; withstands various harsh weather conditions MEMORY FUNCTION: Remembers your last melody and volume level after a power outage; no need to reset to your previous settings; convenient and easy-to-use design for an enhanced user experience