The National Car Test, or NCT, is a roadworthiness test, which all cars in Ireland must undergo. The test must first be taken when the car is between 3½ and 4 years old and then once every two years after that. There are exemptions for certain categories of vehicles such as vintage cars (more than thirty years since date of first registration) and vehicles based permanently on some offshore Islands. The NCT is available in 42 centres around Ireland and tests various aspects of cars for safety, including tyres, brakes and shock absorbers which are vigorously tested. It also tests the exhaust fumes for compliance with EU emissions standards. Other safety features, such as the spare tyre, seat belts and lights are also checked.