Make sure your fish tank is perfectly calibrated with Oase HeatUp Precision Heater! Easy to install with the included holder, this heater ensures accurate temperature adjustments between 66°F – 90°F. Plus, you can make precise readjustments of +/- 2 °F for a truly uniform temperature level. Perfect for anyone looking to incorporate both filtration and heating into one convenient location for the BioMaster - the thermal shutoff switch provides extra protection too!