Copper IUD (Intrauterine Device) or copper T is a small T- shaped plastic and copper device that is placed in the uterus to prevent pregnancy. It can last for 10 years and is reversible at anytime. It prevents pregnancy by releasing copper ions which prevents the sperm from fertilizing the egg. It can be placed inside the uterus by a doctor and be removed at anytime. Copper IUD are highly effective and can be used as emergency contraception if implanted within 5 days of having unprotected sex.