Printed on the solder side and stamped on the component side
overall: 1/2 in x 5 1/2 in x 4 5/8 in
Standard Modular System (SMS) card of unknown function. There are discrete transistors and other components. Covering a fourth of the board. There is an opaque cover over the components. The model number 5300020 is printed in solder on each of these modules.