steering box type

I have seen much on here about 3 and 4 bolt pas boxes yet i cannot work out how to actually identfy which i have on my 200 tdi.Is it the top plate with the bleed nipple on as that has 4 bolts on it or is it the way it mounts to the chassi rail.Any help would be appreciated as mine leaks and i need to source the correct replacement.
Cheers

it is the number of bolts on top plate yours is 4 bolt ,discos are as std

Ok James thanks for that cheers