PFR5-1920 and PFR5-1921 are inserts to be used with the original bushes
PFR5-420 and PFR5-422 are complete replacements for the original bushes
PFR5-1220 is a complete replacement bush for non-M models to raise the front of the rear subframe by 9mm providing the same anti-squat characteristic during acceleration as featured on M model vehicles and is recommended to be used with PFR5-422P
PFF5-4020 only fits the cars with the N55, B58 and S55
PFF5-4632 fits all manual cars before November 2014
PFF5-470 only fits vehicles with manual transmission.