I just got some rear disc's for my MK4 Anniversary from GFS after giving them my Reg and when we got them out to change them they had given solid ones and not Vented

and i wanted to know if they are the same size/fitment as the R32 which are vented rears as well as GFS only do solid for the 1.8T.
I know they are a different part number but i am sure i heard they both shared the same brake set-up? thanks for any help.