Screen printed in the middle of right edge of board on component side. Also etched in copper on the middle of the circuit side.
overall: 1/2 in x 3 1/2 in x 10 7/8 in
This module has "P" LINE DRIVER on both sides. "SPARE BP" is stamped in red on circuit side. The frame is in copper with a connector having 7 socket contacts. The components consist of 7 transistors with many resistors, diodes and capacitors. The copper frame seems to be for grounding purposes. The extractor handle is red.