Catalog, 1981, Black & orange, No. 81, showing misc. products: Four double-sided 11.5″ x 8.75″ (280 x 217mm.) pages; No prices shown; Sixteen products shown; Technical data , including magnet strength, coil resistance, inductance is shown for the newer models only. This information is not shown for the four long-standing products shown on Page 4; DeArmond Inc. Airport Highway.