Dating to the 1940s, this Fowler's Universal circular calculator comes housed in a special blue velvet lined presentation case and accompanied by its original instruction manual. In full working order, the scales perform numerous mathematical functions, including multiplication, cube roots and square roots.

Weighing just over 260 grams in its case, the calculator measures 3 ⅜" (85 mm) in diameter and has a nice, clean dial which is fully functional, with the dial and pointer rotating in either direction, the underside has a black hammer finish steel backplate, which is free of any blemishes.

The black leather case is likewise in excellent condition and measures 4½" × 4⅜" × 1" (116 mm × 110 mm × 25 mm). It comes with its original blue-covered, 50-page instruction booklet, titled 'FOWLER'S "UNIVERSAL" CALCULATOR INSTRUCTIONS' by WILLIAM H. FOWLER.