Knobs made with 2 1/2 and 2 1/4 inches diameters. Plates are 11 1/2 by 3 1/4 inches and 6 3/4 by 2 3/4 inches. Design based on patent number D0018351, May 22, 1888 by George J. Wells.The patent was for the outer rings with any center. Chicago Hardware 1895 catalog showed both this knob andM-11220as 436 Design.