Material: Stainless SteelEffective Length: about 135 mm / 5.4??8 diameters to choose:4 mm / 0.16"5 mm / 0.2"6 mm / 0.24"7 mm / 0.28"9 mm / 0.36"10 mm / 0.4"11 mm / 0.44"12 mm / 0.48"The package come with only one piece of plug.Note: Do thoroughly disinfect before use. Use lubricating fluid， otherwise it will pain， a water-soluble lubricant best.Afterwards， drink more water to urinate.Do not get into reluctantly， in order to avoid hurting urethra.Be sure to slowly expand， do foreplayIf you want more excitement， before you plug in the urethra， insert a vibrator in anus.