These have a clear plastic insert with 2 holes (one to be enlarged for your water/waste pipe and the other an air hole). The internal diameter is approx 95mm.
How to order
We don't like to see customers with missing or broken parts. That's why we always try to keep a stock of spare parts right here at Kiravans HQ. All you need to do is find the part you need and let us know what it is and where you want it sending by emailing firstname.lastname@example.org or by calling the team on 0113 804 2125.
We don't charge for this service, all we ask is for a small donation to a charity of your choice :)