CHA Industries GT411 thermocouple vacuum gauge.

The gauge measures 145x30mm (40mm across the flange near the base). The opening is 6mm inside diameter.

Base - standard octal male
Heater pins 1 & 5
T.C. pins 3 (-) & 7 (+)
Heater current is 0.64A (0.6A plus the hundreths marked on the nipple - 4 in the case of this one, making 0.64)
T.C. output 14mV DC @ 0.1 to 1 micron of mercury.