* Variable power output.
2 years guarantee
Carbon Classic Waterbed Heater.
Suitable for all sizes of waterbeds.
*This means it automatically keeps a constant waterbed temperature using variable power output and a thermostat. If the water temperature in your bed is cold it will output up to 270w into the heater pad to warm the water quicker. When your bed is approaching the desired temperature or to maintain the desired waterbed temperature, the output gradually reduces to 210w until the thermostat switches if off. (Energy efficient). When it detects a 1/3 of one degree drop in temperature then it automatically switches on again, this cycle keeps on repeatedly, accurately and automatically keeping the bed at your chosen temperature.