I'm trying to find a fitting made by Valterra It is a 3 inch male thread to a 3 inch bayonet. This where you fix the sewage line to.
Any help appreciated.

Try here for Valterra T1029-4

https://jet.com/product/detail...aJtsgCFdgRgQodnMgAlw

There are others listed on Amazon.com, Ebay, etc Good luck, mate.

Complete line of products here, competitive prices: www.valterra.com

Thank you for your help
Regards Keith