While you're buying a cap and rotor, I would suggest getting only Bosch parts. The quality of the Bosch over the aftermarket cap and rotor is amazing. The body of Bosch rotor looks to be ceramic, and is considerably more substantial in weight. The quality of the cap is also plainly obvious.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.