BMW 323 328 528 M3 Z3 Mass Air Flow Sensor Meter MAF # 5WK9600 #13621703275 1996 1997 1998 1999 2000 2001 Brand New Replacement Mass Air Flow Sensor ( MAF ) Siemens Ref. # 5WK9600, 5WK9617, 5WK9600Z BMW OEM Ref. #13621703275,13621703650,13221702078 This MAF has an inside diameter of 78mm This MAF has a 4 pin connector