Hydraulic tensioner for BMW 5 Series E39 gasoline

Automatic hydraulic cylinder tensioner in aluminum of alternator and water pump beltfor BMW 5 series E39 gasoline:

E39 Sedan and Touring:
- 520i (engine codes M52B20TU and M54B22)
- 523i (engine codes M52B25 and M52B25TU)
- 525i (engine code M54B25)
- 528i (engine codes M52B28 and M52B28TU)
- 530i (engine code M54B30)

Delivered alone with no idler or mounting hardware.

PLEASE NOTE: there are 2 possible assemblies, one with a mechanical spring tensioner (part number BD30310) and one with this hydraulic jack tensioner. Please check your assembly before ordering!