This wiring harness is needed for the Single-Pole Double-Throw Relay to make connection so much easier and mess free.

This is a Simple quick connect Socket for the HFV4 relay. These are a standard harness to fit the a SPDT 30/40 amp 12 volt relay (sold separately) Includes approx 10" of cable length

These can be used in a variety of ways, but this relay harness is a great way to control the DC motor of a linear actuator. In order to achieve start/stop/direction control of a linear actuator you need to use two SPDT relays. With the two SPDT relays you can cut the voltage/circuit to the motor and swap the polarity going to the linear actuator motor.

Another advantage of using two SPDT relays to control a linear actuator is you get active or dynamic braking of the linear actuator allowing you to essentially "stop on a dime".

There are many other uses for relays, and this relay harness is a great way to wire up the relays.