The AllPoints Foodservice Parts & Supplies 221658 Thermostat Knob is designed for precise temperature control in various foodservice equipment. With a diameter of 2-1/2 inches, this knob features clearly marked settings: Off, Lo, 2-7, Hi, and Preheat, allowing for easy adjustments. The 3/16" D-stem flat design ensures compatibility with a range of models, including Star Wells warmers and several SS series units. This durable and reliable component enhances the functionality of your equipment, ensuring optimal performance and consistent results in food preparation and holding.