The hollow is very compatible and there are many ways to play. For example, water injection, enema, cleaning, liquid injection, etc., and it can also be matched with other toys.Function: Silicone Hollow Butt PlugColor: BlackSize:S: 9.0 * 4.8 cm /3.55 * 1.89 inch (75 g/0.17 lb/2.65 oz)M: 11.5 * 6.1...