Hi there 400, and welcome to ECN! [Linked Image]

The Robin range of equipment does seem to be gaining popularity in the U.K. in recent years. Their website is a bit long-winded to find anything, so here a direct link to the KMP4120DL.

I still have an older Clare V159 loop tester. Nice instrument still built in their traditional-style wooden case, but unfortunately it does trip out an RCD.