Cap diode inverter 4129-E System Building Block
A paper tag attached reads "Reject Missing copper". On the solder side an attempted repair can be seen. The part number is covered by red marker and the blue marker letters "MT".
Digital Equipment Corporation (DEC)
||Etched on solder side
||Engraved on end
||Engraved on side
overall: 1/2 in x 7 in x 4 1/2 in