High Quality and economical these tank heaters are completely submersible with double insulation. Heater thermostat with temperature settings and easy to read temperature guide with automatic shut off and on light. Specifications; 50 watt – suitable for tanks up to 50 litres* 100 watt – suitable for tanks up to 95 litres* 200 watt – suitable for tanks up to 190 litres* 300 watt – suitable for tanks up to 280 litres*