Diaphragm and Caps

The contraceptive diaphragm is a circular dome made of soft, thin silicone. It’s inserted into the vagina before sex and covers the cervix so that sperm can’t get into the womb. You need to use it with a gel that kills sperm (spermicide). Caps are smaller than diaphragms, but they work in the same way.

How effective is the diaphragm and cap?
Advantages
Disadvantages