Which center caps to buy.
 

We have a set of alloy rims and need to purchase Honda center caps. The rims were available on Acura vehicles and Honda vehicles. The Acura part number is: 42700S5DA31. I understand the Honda part number is: 42700S5DH31 but I may be incorrect. How do I know which size center caps will fit?

I've asked my local dealer and much to my dismay I was told to check online. I guess they won't be getting my business for this purchase. I'd like to purchase the center caps before we switch to summer tires as the alloy rims are for the summer tires.