They are a widescan coil originally intended for the lobo Super Trac. Very very very rare coil. Will work on any 4 pin machine.
You got really lucky there.
That's the only coil I know of that can't really be found.
My Troy super 7 was pretty rare but because it was offered on a detector there were many sold.
The coil you have was strictly an accessory coil and back then I don't believe the HOT 4 pins were out so the lobo may have been the only detector able to use it, but don't quote me on that.
If I owned that coil, I would send it into Tesoro with a $50 check and have them make sure it's in top shape. They may have to rebuild/retune it, but that's a coil is send in.
When I got my Troy, I sent my Deleon I had just gotten in with it to kill two birds with one check lol. Had it rebuilt and also had my Deleon tuned to it. Great combo but it was worth the $50 to me to have the coil put back in perfect working order (or as I thought at the time to have it checked)