Amazing Gear Ring. The Gear Ring is made from high quality matte stainless steel. It features micro-precision gears that turn in unison when the outer rims are spun (as can be seen in the video). It is currently available for purchase in twelve standard US ring sizes: 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 & 16.