Display time, temperature and humidity Fahrenheit and Celsius conversion With 4 adjustable volume levels ranging from 0 to 100 dB Long-distance ensures you hear and answer the doorbell in time Easy to set up, just plug the mini receiver into a socket and fix the transmitter on a wall A perfect wireless doorbell kit for home, apartment, villas, office, hotel, factory, and more Specification: Product: Wireless self-powered doorbell Material: Mirror material Type: 1 transmitter + 1 receiver Waterproof rating: IP44 Working temperature: 0°C to 99°C Working humidity: 0% to 99% Working frequency: 433.92MHZ+ 75KHZ Receiver voltage: 100- 260V/50- 60HZ Transmitter battery: no battery required Ringtones: 38 songs, learning code, DIY Volume: 0-100 decibels, 4 levels adjustable How To Use: 1. Song selection button: press the button once to play, press again to play the next song. 2. Volume button: maximum volume after power on. Press once to select mid-range, press again to decrease the volume, and press again to mute. 3. Time setting key: Long press for 3 seconds to enter the time adjustment mode, short press the setting number, the interval between two seconds is the jump interval, after 3 seconds, do not perform any operation to exit the automatic setting. 4. Key cycle: switch between Fahrenheit temperature and Celsius temperature. 5. Method code: Long press the volume button, then press the transmitter.