A copper IUD (intrauterine device) is a small, T-shaped device made of plastic and wrapped in copper. It is inserted into the uterus by a healthcare provider to prevent pregnancy. The copper releases ions that create an environment hostile to sperm, reducing the chances of fertilization. It can remain effective for up to 10 years, depending on the type. The copper IUD is a non-hormonal form of birth control, making it a suitable option for those who prefer to avoid hormones. It can also be used as emergency contraception if inserted within five days after unprotected intercourse.