Lloytron b7511 door chime mi p system this product can be programmed to add other mi p door chime and bell push modules features up to 4 transmitter and 4 receiver mi ps modules can be programmed at once plugs into any standard uk wall socket large flashing strobe for hearing impaired strobe onoff switch 150m range choice of 32 melodies waterproof bell push battery included low power consumption colour white