Here you can find different wheel spacers weights.

HR 12mm spacer for the CSL. 401g

An Eibach 12mm spacer, 477g
It is 76g heavier than the H&R 12mm spacer !

Here is an H&R 20mm spacer (with the extra bolts).
Together with the extra bolts 1037g

Without the bolts 805g

The bolts on their own 231g