Noob question: Easiest way to tell which type of Z32/R32 calipers ?

SON240sx Automotive
1

I’m not sure if I have the 26mm or 30mm ones and I’m looking to buy pads/rotors sometime soon what’s the easiest quickest way to check?
(I googled, and got nothing, I googled it like 4 different phrasings)

All I can see is they’re black with “Nissan” in white.

2

Here is the info you need:

3

thanks