IBM tube modules
There are two mini tube modules. One has a tube in place and the other does not. There are two rows of resistors and other components. At the bottom there is a male 9 pin connector.
International Business Machines (IBM)
||Printed on the vacuum tube
||Printed in white on the vacuum tube
overall: 6 in x 1 in x 1 1/2 in
Gift of Paul Pierce