Simply fantastic value alarm set with 3 alarms, sounder box & 3 way cable. Proven reliable performance at a simply stunning price. Separate Tone & Volume controls. Two Hi-Vis LEDs. Volume Control doubles up as an on/off switch. Jack Plug Socket. Sounder Box has a volume control & three individual LEDs plus strong spring clip arrangement for easy fixing. Supplied with three-way 10 m. extension lead. Each indicator is powered by one PP3 9v battery (not supplied).