Found printed in white on black rectangular component
overall: 2 1/2 in x 5 1/2 in
This is a B155 module with a green board and a blue plastic extraction handle attached by two rivets.The component side is marked with three inspection stamps. The square stamp reads "Tested 3 A.M.T.8". "HALF BINARY TO OCTYL DECODER B155B" is stamped on the solder side.