When this doorbell rings, the sound is accompanied by several bright flashes from the receiver's built in strobe light, which makes it much easier for a hearing impaired person to know that someone is at the door. The sounder can be taken from room to room, or even used outdoors and will work up to 30 metres from the transmitter button. The melody can be set to one of seven different sounds and has two volume levels - medium and loud. The unit is supplied with a neck lanyard and mounting hardware for the transmitter button.