Hi hi All help appreciated. Bit of a DIY newbie, cracking on as best I can. Hopefully this makes sense. Renovating downstairs WC of recently purchased house. Upon ripping everything out I discovered the outlet is a fixed, angled, 110mm pipe straight into ground (concrete) with no vent as per picture. It is not movable/cannot be turned, and sits very close to where the toilet outlet will be. I wanted to attach a Durgo / AAV and struggling to see how to make it work. Option 1 - flexi pan connector with bose vent on top - through push fit connectors, attach the 32mm vent (on top of pan connector) to 40mm pipe and then to 110mm pipe for a standard sized AAV. Concern is the narrow pipes not allowing sufficient airflow from the 110mm and whether that causes problems. Option 2 - as above but instead of on to 110mm pipe / AAV, use a smaller AAV that fits 40mm pipe. Concern again is airflow due to smaller AAV. Option 3 - saw through the fixed outlet pipe below the curve to allow 110mm T-pipe to be connected via pushfit connector which hopefully sits vertically. That allows the pan connector to be attached to the side whilst leaving 110mm top opening. Concern with this (1) as far as I can see the fixed outlet in the ground is 110mm. However, once I saw through its the point of no return. If it turns out to be 100mm or 115mm etc I will need some kind of insert connector to sit inside it to connect the T-pipe. Worried about sawing that and then struggling to find what I need. (2) I need some kind of flexi connector in the tope of the T-pipe to bring the 110mm pipe that goes up to the AAV over to the corner of the room to allow room for the cistern. And generally I have no idea if these connectors exist / fit. lots going on there and just struggling to think how best to tackle that. All ideas much appreciated.