This is a Luminous cock ring , glow in the dark Material: Metal Color: Silver Ring Inner Dia:  S: 26 mm/1.02 inch (40 g/0.09 lb/1.4 oz  ) M: 28 mm/1.1 inch (45 g/0.1 lb/1.6 oz  ) L : 30 mm/1.18 inch (49 g/0.11 lb/1.7 oz  )