The PhimoRing Stretching Ring Kit for phimosis stretching is made out of premium, hypoallergenic silicone that has been tested by the European Parliament and Union standards. Each package includes 20 rings, one ring in each of the following size: 3mm, 4mm, 5mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm, 24mm, 26mm, 28mm, 30mm, 32mm, 34mm, 36mm, and 38mm.