Guide pulley, Timing belt

Additional info:
There are two sets of drives. Volvo has neither a registration nor an engine number to distinguish it from. It must therefore be checked on the car.
1) The timing belt is mechanically tightened.
 (The tensioner is pressed with a spring)

2) The timing belt is hydraulically tightened
 (The tensioner is pressed by a hydraulic cylinder down to the belt)

744, 745, 764, 765, 780. All models with four-cylinder four-valve gasoline engines
944, 945, 964, 965. All models with four-cylinder four-valve gasoline engines

OEM# 3531279