Yeah. Most are specialist. You're best off with one of the two(?) standard screens (split + matt or split + grid I think) ... not sure which code those are of the top of my head. Will check tonight.
I got one (to replace some macro screen and match my other OM).
Have you got a decent focus screen fitted?
There's a bunch:
http://esif.world-traveller.org/om-sif/findergroup/focusingscreens.htm