The Rotem EMU (also known as K-Train/K-Stock) is an electric multiple unit that operates on the MTR rapid transit railway system in Hong Kong.

The K-Stock trains came under criticism when they were first put into service due to delays and door safety issues.

MTR anticipated that the opening of the Disneyland Resort and Ngong Ping 360 would have an increase in passenger demand and therefore ordered four new trains for the Tung Chung line.

The time frame from order to completion is short in comparison to other stock, however; the four new trains can only be made to be identical to existing Tseung Kwan O line K-Stock.

A variant of the MTR K-Stock EMU was selected as Phase I rolling stock for the Delhi Metro in India.