The AllPoints Foodservice Parts & Supplies 224478 is a durable burner valve knob designed for reliable performance in foodservice applications. Featuring a sleek chrome finish, this knob has an outer diameter of 2-1/2 inches and a 1/4-inch D-stem with a flat down design. It includes a set screw for secure attachment. For those needing an alternative, the AP# 221648 offers the same knob with an opposite D-stem configuration. This product ensures easy operation and enhances the functionality of your equipment.