Features: 433MHz home remote control digital LED wireless induction doorbell 3 levels of volume adjustment 38 music Mercury-free lead, and ultraviolet light, green energy guarding the earth zero pollution Simple installation sensor should be installed at a height of about 2 meters receiver plugged into the electricity can Built-in dual speakers, clear sound, especially suitable for home, office, factory, store, security welcome and other places IP52 waterproof, deep waterproof slot + high waterproof cover, wind and rainproof Specification: Types (Optional): One Probe with One Host, One Probe with Two Hosts, Two Probes with One Host Standards (Optional): American, British, European Receiver Operating Voltage: 110-240V Transmitter Operating Voltage: 4.5V (3x7 Batteries not Included) Working Distance: up to 70m Transmitter Sensing Distance: 3-7m Transmitter Size: 9x8x5.3cm Receiver Size: 8x7.6x3.3cm Quantity: 1 PCS Receiver Keys: Music: 38 pieces of music optional, the side of the music logo button to adjust Volume: three levels of volume adjustment (high, medium, low) side of the volume mark button for adjustment can be set with sound and no sound (sound: sound + indicator light no sound: indicator light) Package: 1x Intelligent Doorbell