One interesting little temperature instrument rated -50 to 150 degrees C. as manufacted post-war by The Lewis Eng. Co. It identifies as a Spec. No. 21296. It's a ROUND instrument as fitted with a special 2" square holder for panel mounting applications.

Data plate on the rear of the instrument reads:

INDICATOR, TEMP. ELEC. RESISTANCE

The bezel mount is marked with:

Looks like the face is stamped US TYPE G - 8 

This is a ROUND 1 7/8" instrument - most folks would simply refer to it as a 2" instrument. The order number on the data plate would usggest a 1947 order prefix for either USAF or USN application.

Powered by a 4-pin Cannon electrical connector end.  Nice sharp graphics - sort of a dark mustard color. I see no drop damage or dirt or moisture or bugs behind the glass. The mounting front is loose permitting you to index the instrument in whatever position you desire in the panel. The instrument is metal cased. If you need  90 degree or straight electrical connector to power instrument, inquire. We can supply for extra cost. 

Nice vintage instrument - a great panel filler if you needed it.

Ships cheapest via USPS Ground Advantage or FedEx Ground unless you direct otherwise. Questions? Please ask seller.  And thanks for looking!