Outdoor IP44 transmitter with call button and name tag, 63x27mm, plug-in receiver, 106x34mm, with 15 adjustable ringtones and adjustable volume, 75db volume, range approx. 100m, easy transmitter and receiver programming, expandable to up to 4 radio transmitters , radio frequency 433.05-434.79 MHz, 230V/AC mains operation receiver