I am laying a light-use patio with 22mm thick sandstone flags. In the
proposed area there are a couple of small inspection holes (211 mm
diameter) with square plastic osmadrain covers (325 x 325 mm).

Here is a link to the product page for a clearer idea:
http://co-uk.wavin.com/master/master...oduct_detail_I

I'm trying to find recessed covers to replace these - you know the
type where you can cut and lay the flags inside a recessed tray to
give a nicer appearance. More usually they are for driveway block
paving. I am lost in all the descriptions & designs when searching
the web.

Does anyone have any pointers to get me closer to what I want? Any
help appreciated!

AA