Product details Top highlights HIGH PERFORMANCE TRANSMITTER: Ultra-low power consumption; uses a lithium battery that boasts 3 year maximum lifespan; IP55 dustproof and waterproof; working temperature ranges from -4 °F-140 °F; withstands various harsh weather conditions 1300 FT / 400 M WIRELESS RANGE: 2 plug-in receivers included; will not interfere with other equipment in your home or those of your neighbors; ensures that you will never miss any visitors, even if you are several rooms away 52 BEAUTIFUL CHIMES: 40 mm stereo speaker delivers rich and crisp sound; press the Next or Previous button to easily choose from 52 melodies; 5 adjustable volume levels, with a maximum volume of 115 dB; enjoy pleasant melodies whenever someone rings at your door MEMORY FUNCTION: Preserves your last set melody and volume level after a power outage; no need to reset to your previous settings; convenient and easy to use design for a better user experience EASY TO SET UP: Additional AVANTEK RB-1/CR-1 plug-in receivers can be added to enhance coverage; the package includes 2 screws, 2 anchor plugs, 1 key, and 1 adhesive patch for easy installation of the transmitter See less Product specifications Manufacturer ?AVANTEK Part Number ?D-3B Item Weight ?9.9 ounces Product Dimensions ?7.72 x 2.32 x 4.21 inches Country of Origin ?China Item model number ?D-3B Batteries ?1 CR2 batteries required. (included) Is Discontinued By Manufacturer ?No Color ?Black Material ?ABS Voltage ?3 Volts Item Package Quantity ?1 Included Components ?2 × Plug-in receiver, 1 × Transmitter (battery included), 1 × Adhesive tape, 1 × Screwdriver, 2 × Screw, 2 × Anchor, 1 × User manual Batteries Included? ?Yes Batteries Required? ?No Battery Cell Type ?Lithium Manganese Dioxide Average Battery Life ?3 years