Printed upper left corner and on the wiring side board
overall: 8 1/2 in x 26 in x 11 1/2 in
Object is a large metal panel bearing 16 BNC connectors and one multi-pin male connector. There are sockets for 5 vacuum tubes of which 4 are populated. On the wiring side is a red gummed label with the text "PAT. NO. 3.489.433".