For a hardcore hard on, there's no better erection enhancer than the Double Helix. Designed to fit around your cock and balls, this will harness your erection and keep you up as long as you please. Easily sized to fit your penis, it also features a quick release system to let you down when you're ready to call it quits - but not a second before! Trim-to-fit quick release double erection enhancer Rubber 2.75”/7 cm (large ring/diameter) 2.25”/6 cm (small ring/diameter)