A throwback to the past.
I assume that is a handheld TC. The internal circuitry of that handheld digital gadget would have been black magic in 1960. It would have taken a computer the size of a small file cabinet, or the Apollo landing computer. The digital display would have been Nixie Tubes. Which, I am amazed to discover, you can still buy:
Marvelous things, but not small. Complicated, and hot. You cannot drive them with a handheld battery.