Model: FF400. SEALEY Car/Van DC Open/Short Circuit Detector/Tester/Tracer 6v/12v/42v. Sealey Open & Short DC Circuit Detector 6v - 42v. Simply attach the sender unit to the circuit and follow the wires using the detector.
Bought it to find where the reverse wire had stopped feeding the lights on my car and without it i'd still be searching and stripping the wiring loom, found it literally in seconds just past the reverse switch right in the middle of the wiring loom where the wire somehow got cut by the holding clip.
saved endless time, hassle and headaches. would definitely recommend.
The only thing i think would finish it off would be if it came with a fuse adaptor that i bought separately as ideally it should be connected to either end of the fuse of the circuit you need to check.