Gruen was the patent-holder of the Curvex design, and they created innumerable and ever-longer cases curved to fit the wrists of an insatiable American public. Here is a 20mm x 47mm design, circa 1936, with its slim curved case, matte dial with gilt hour markers, subsidiary seconds register, and 17 jewel manual wind movement warrantied by Aaron Faber for 12 months.