I recently got to play with a set of the test leads described in this video, and had mixed reactions with them. Circuit testing is quick...two tests and you're done. The video and tool directions both say to move the ground probe to a good mechanical ground point and since a lot of heavy equipment techs use this tool, I guess that works out just fine. Me, I still want my ground reference at the battery. TESlite is a small outfit, and getting questions answered is easy...just a phone call or email away. The tool has been assigned part numbers by Caterpilar and Volvo Heavy Equipment, as well as a few others...so there must be something to this tool. I have not actually used it yet to solve a problem, but I decided I'd post his training video with links to others so you can judge for yourself.