Item replaces OEM plastic fitting on BMW Part Number 11537541992 and 11537544638 with a Billet 6061 Aluminium piece. 335i, 335xi, 135i and the N53 (3.0-litre non-turbo) 2006 - 2010. Simply remove the end of the hose from the plastic fitting and then the fitting from the head (hose does not need to be removed from the thermostat housing to do this).
