Rapido sink insert (1 Viewer)

[Harco]

My Rapido has 2 roundish sinks.
The main sink has a glass flip up lid.
The other has a plastic tray that sits within the sink with a chopping board above.
The tray has a round cutout on the straight edge and a lip that looks like it should lip onto something.
The question is does it fit somewhere or is the lip etc just for show?

 

[laird of Dunstan]

we put the spare one in the window out of the way,it just slots in nicely