This plugboard has white printed lettering and numbering along the wooden grid. At each end two metal nails hold the grid in place. The back is covered by many male interfaces.
International Business Machines Corporation (IBM)
||Inlaid at the top of the plugboard
overall: 10 1/2 in x 6 1/4 in x 1 1/4 in
Memory/connector / plugboard
SAP Collection, Computer History Museum