The cervical cap is a reusable, deep silicone cup that is inserted into the vagina and fits tightly over the cervix. Furthermore, the cervical cap can be inserted hours before sex and remain in place for up to 48 hours, which does not require any partner cooperation.
Cervical caps are smaller than diaphragms and the shape is a little different: diaphragms are shaped like a dish, and cervical caps look like a sailor’s hat. They both work with spermicide and cover your cervix to prevent pregnancy.
You can leave the cervical cap in longer than a diaphragm (up to 2 days), but diaphragms are slightly more effective at preventing pregnancy. Your nurse or doctor can help you decide which one is better for you.