Optimum Ecosave 7 quartz Immersion Timeclock24 hour water Heater time switch for single/dual or twin immersion Heater applications programmable every 15 minutesSuitable for combination storage/convector heaters with a 15 to 120 minute adjustable boostIndicator lights display on, Peak and boost outputsContact rating of 16A at 230V 50Hz and a running reserve of 72 hoursComes with manual on/off switch