Kit contains three rings. #20, #21, and #22. 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. Features: Ring Number 20 2 inches in diameter, 6.3 inches circumference. Ring Number 21 2.1 inches diameter, 6.6 circumference. Ring Number 22 2.2 inches in diameter, 6.9 inches circumference.