Group of 69 solar cells produced by Hoffman Silicone Devices, each measuring 3/4˝ by 3/8˝, housed in their original 10.25˝ x 6.5˝ x 1˝ box. In overall very good to fine condition, with soiling and an ink notation to the box. Hoffman made the solar cells used on Vanguard I, the world's first solar powered satellite.
