This record contains four sheets of copper masks. These masks are used for single channel tube parts. The sheets have borders of solid copper with spaces for the masks in the middle. The masks are connected to the sheets with thin strands of copper so that they can be easily torn off. Three of the sheets are close in size and one of the sheets is larger.
Dimensions
big sheet: 1/8 in x 6 3/4 in x 4 3/8 in; small sheets: 1/8 in x 5 1/8 in x 2 7/8 in