It has both, the belt is on the left hand side of the engine and has to be replaced as described. There is a chain on the right hand side of the engine and is actually internal and not intended to be a 'service replaceable' part. A lot of people have been complaining about noisy engines at idle and its been found that the cause is a worn chain and tensioner ...
Does the OP have this problem or have they got their terminology mixed up?