Found on solder side near extraction end. "8b" has been added by hand to number
overall: 3/4 in x 3 5/8 in x 7 1/8 in
This Z23 circuit board has the remnants of a label on the component side near the insertion end. There is also one square inspection stamp. There is another label remnant on the solder side. There are two inspection stamps on the circuit side: one square and one round.