AmScope Simple Polarizing Kit for Compound Microscopes A simple polarizing kit with a round stage and polarizing lens. Mounting size of the lens: 1-1/8" (28mm) in diameter. Size of round stage: 2-3/4" (70mm) in diameter. Size of observation hole: 5/16" (8mm) in diameter. Dimensions of rectangular plate: 4" x 4-5/8" (100mm x 65mm).