LLNL deprecated number, written on the back of the object
overall: 1/8 in x 8 1/4 in x 4 in
The object is a metal plate somewhat larger than an IBM punched card. A paper test card apparently slides into place under three metal tabs so the user can check whether the punches in the card line up properly with the markings on the object. Written on a label attached to the back of the object is "THE REGISTRATION OF ALL CARD PUNCHING EQUIPMENT SHOULD BE CHECKED ONCE EACH DAY [and other, similar text]."