This clock is an original GM wind up clock. It is in extremely nice condition for its age but not perfect. Because it is a windup clock, you will need to wind the stem regularly to keep correct time.
The hole in the center of the back is for a light socket with bulb which illuminates the clock when the dash lights are turned on. Because it is a windup clock it can be used with 6 or 12 volt systems simply by changing the bulb.
The chrome is nice but does have some imperfections, the glass and lettering are clean and not cracked or crazed. The knob is not burred but from used does have some brass showing. I do believe you will be happy with clock.
I have priced this clock $40 cheaper than the last clock I listed because of these minor imperfections
