This is an exceptional product! The relay adapters allow the user to easily check the presence/absence of signals to a relay. The relay pliers are an exceptional bonus for the kit. It provides enough mechanical advantage to extract a relay without causing damage or marring surfaces. The relay pliers can also be used to disconnect automotive connectors; for example removing tough connectors to a fuse box.The biggest benefit of this kit is the jumper wires! The wires have various male & female attachments that can plug into sockets or pins. The jumper wire set also has a ground wire set with fuse protection in addition to a metal clamp that can attach to chassis ground. This jumper wire set easily interfaces with multimeter leads too!Bottom line: Excellent tool for troubleshooting relays, electrical wires in a car, or other electrical project. The jumper wire set and relay pliers may become the most used items from this kit! They have already paid for itself in reducing troubleshooting time!