The hardest erection you've ever had. 

3 Ring sizes 
Body safe silicone 
Phthalates free 
Waterproof 
100% Silicone 

Large Ring: 
Outer Diameter: 2.5 inch (6.35cm) 
Inner Diameter: 2 inch (5.08cm) 

Medium Ring: 
Outer Diameter: 2 inch (5.08cm) 
Inner Diameter: 1.5 inch (3.81cm) 

Small Ring: 
Outer Diameter: 1.75 inch (4.45cm) 
Inner Diameter: 1.25 inch (3.18cm)