Coolant pipe to thermostat seal size

[sp09]

Hi all changing thermostat on my a3 sport back 09 late wants to change the seal on the push fit connector onto the thermostat houseing does anyone mow what size this is or a part number for it? cba engine themostat housing has four pipes connecting to it 3 with a clip one push fit

 

[sp09]

and does this matter if not changed as he says has done loads and they have always leaked after ?

 

[Keram]

06B121687

 

[sp09]

06B121687

Brilliant thank you

 

[sp09]

so been let down on someone fitting for me looks like will have to sort myself