The Whirlpool W10552121 Range Surface Burner Orifice Holder is a modest but essential part of your gas range. This is a metal container that securely holds the orifice, a tiny nozzle that regulates the flow of gas to a particular burner. The orifice holder screws into the burner's base and connects to the gas line. When you turn on a burner knob, gas goes along the line, into the orifice holder, and out of the perfectly designed orifice, resulting in a focused flame. A defective orifice holder can create a variety of issues with your gas range. A loose holder can cause a gas leak, which poses a safety risk.