Interchangeable with Sangamo and Horstmann Economy 7 units. Suitable for use with single, dual or twin element immersion heaters.  Designed for use with Economy 7 off peak rate overnight electricity plans.  4 Boost demand options – 15, 30 minutes, 1 & 2 hours.  24 hour Segment dial with minimum 15 minute switching intervals.  Output LEDs illuminate during off-peak and boost periods.  Quartz reserve with 150 hours memory back-up.  Fits and supplied with a standard size Economy 7 wall box.  IP30 enclosure protection.  Class 1 shock protection.  Contact rating: 13A suitable for immersion heaters up to 3kW.  Operating temperature: 0°C to +35°C.  Contact type: Micro-disconnection ON control.  Disconnection to immersion heater(s) via double pole rocker switch.