The Vulcan Hart 00-833220-00011 is a 2-1/4-inch diameter thermostat knob used for temperature selection on compatible jacketed kettle controls. Its marked surface gives operators a clear reference when rotating the control to the desired heat setting. The knob provides a direct interface between the operator and the kettle thermostat, making temperature selection simple during normal operation. It may be needed when the original control knob becomes cracked, loose, difficult to turn, or unavailable. Confirm the kettle model, control configuration, and part number before purchasing to ensure this knob matches the intended application.