This part is extremely helpful for adding gauges or other electronics to your car. Just select a circuit and remove the existing fuse. Replace the fuse with the Add-a-Circuit harness, then put the fuse in the empty slot in the Add-a-Circuit. You now have a convenient spare 5-amp power tap to power your gauges. If you ever need to reverse the process, just put the original fuse back in its original slot, and remove the Add-a-Circuit.
Fits most import cars with mini-size fuses.