I was talking with a friend that’s just getting into thermal and mentioned that the first personal usable thermal unit I could remember was a handheld unit that registered heat sources with a set of lights, the stronger the source the more lights showing and you registered direction by moving the unit side to side and noting where it registered strongest

That’s about all I can remember about it no name no mfg and I believe it came out in the 90s

Anybody remember it and who made it

If I remember correctly it could also be mounted to a rifle scope