Find the perfect fit! Expand the versatility of your favorite SportSheets strap-on harness with four sizes of rubber O-rings. These moderately stretchy, latex-free rings allow you to affix new and exciting dildos from extra-small to extra-large to your favorite harness. Alternately, you can choose your ideal size and tightness to wrap around you penis or your balls and penis, and use them as a cock ring. With restricted blood-flow, your erection will be harder, more sensitive, and longer-lasting than ever before.Measurements: 1.25" (3.2 cm), 1.5" (3.8 cm), 1.75" (4.5 cm), and 2" (5 cm) in diameter