KLIA connects the city with direct flights to destinations in six continents around the world, and is the main hub for the national carrier, Malaysia Airlines and low-cost carrier, AirAsia. KLIA can be reached using the KLIA Ekspres, an airport rail link service from KL Sentral, which takes twenty-eight minutes and costs RM 55 (roughly US$13.50), while travelling by car or bus via highway will take about an hour but cost a lot less. Direct buses from KLIA to the city centre are plentiful (every 10 to 15 minutes during peak hours), air-conditioned and comfortable with fares ranging from RM 11 (roughly US$2.70) to RM 15 (roughly US$3.70). Air Asia and other low-cost carrier flights do not fly out of KLIA main terminal but from KLIA2 which is two kilometres from KLIA. KLIA2 is served by an extension of the KLIA Ekspres and by a free shuttle bus service from KLIA. , Sultan Abdul Aziz Shah Airport is only used for chartered and turboprop flights by airlines such as Firefly and Malindo Air.