The Fermenting Heater can be safely adhered to your carboy, brew bucket, or conical fermenter to assist with fermentation temperature control. It distributes 40 watts of heat gently over an area of 2 square feet, raising the temperature of your fermenter by 5-20 degrees. Electrical tape is recommended to secure the Fermenting Heater to your fermenter. For the ultimate temperature control, use the Fermenting Heater in conjunction with a Stopper Thermowell and a Johnson Digital Controller. This combination will allow you to control your fermentation temperatures to within a few degrees!