The kit allows testing of relay configurations not covered by our eight Relay Test Jumpers, for example: relays found on Volkswagen, BMW and other European vehicles. The in-line switch gives the ability to control the circuit on and off. Stacking banana connectors on the switch allow technicians to connect a multimeter into the circuit to test the voltage or current, providing a series break-in point to eliminate the need for a clamp on meter. The circuit can be powered for testing by using the power lead connected to the 12 volt positive side of the battery. The kit works without piercing wires.