This set of half-round plastic finger gauges measures the size of fingers in 4 different sizing systems: diameter (mm), American, European, and Asian sizes. Each of the 36 finger gauges is marked with the 4 different sizing systems. Sizes range from 12.37mm (US size 1) to 24.2mm (US size 15.5). The gauges come on a steel ring, and can easily be taken off or rearranged. Each gauge is 3.5 mm wide and very sturdy. The sizes are divided into 3 different color variations to differentiate small, medium, and large sizes.