MTR KTT
 KTT (Chinese: 九廣通)) is a train set used by the MTR Corporation Limited in Hong Kong on the cross-boundary service to Guangdong route. The KTT is not the only service from Hong Kong to China Guangdong service is also provided by the mainland Chinese railway operators.The double-deck KTT trailers have lower bottom floor than the ordinary cars serving on the same pair of tracks.