The built-in vagina is fixed with in the doll’s body, just like a real woman’s, giving you a more authentic experience. The removable vagina is a tube with a smooth surface and inserted bumps that you can insert and remove from the doll. Most of our customers choose the fixed vagina because it is more realistic, however, the removable vagina is more conducive to cleaning. If you are very focused on the real experience, the built-in vagina is recommended for you, but if you prefer something that is easy to clean, the removable vagina would be the way to go.