Thanks Bahco for your help, thats exactly the part I'm looking for.
It's a pity peedoff_rgi has the inability to grasp the forums purpose... **** for brains!
I have a basement flat and the bathroom toilet, bath and sink waste pipes all connect to one outlet. It is oval in shape and has separate holes for the toilet waste and smaller bath and sink wastes to go into. There is also a spare inlet hole which is capped off.
I need to get hold of a cap...