Perfect Fit - Xact Fit Silicone Rings
Perfect Fit has developed the first cock ring sizing system designed to fit you without too much pull but with enough restriction to be truly effective.
Ring Number 14: 1.4 inches in diameter, 4.4 inches circumference
Ring Number 15: 1.5 inches diameter, 4.7 circumference
Ring Number 16: 1.6 inches in diameter, 5 inches circumference