I use World's Best from Mike Sandman.
I have seen a lot of Progressives (now Tempo Electronics), though.
........., on the surface it seems like all are pretty much the same
The best toner, IMO, is by Fluke. If you short out the two wires the toner is hooked to for a second, it changes tone, which allows you to verify that you actually have the correct set of wires. That feature has saved me countless hours over the years I have used my Fluke toner.
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