The AQK3 Flame Diode Test Adapter Kit allows you to plug into the flame diode circuit between the controller and the flame sensing rod to check for problems. Whether you"re testing a system with a hot surface igniter or a standard burner and flame setup, the adapter kit includes both a pair of spade connector leads to enable easy connection from the AUA2 or a millimeter to quick connects, plus an adapter for controllers that require a mini-plug connection.