This vintage 1944 Perry Graf radio tube pin data slide rule, designed by Harry Langsam, is a rare find for collectors of radio and phonograph memorabilia. Made in the United States, this two-sided slide rule features accurate data for radio tube pin connections. The design is a testament to the craftsmanship and precision of the era, and is sure to add value to any collection. The brand and country of manufacture are clearly indicated, making it a valuable addition to any collection of vintage radios.