Glow plugs

[Nightfury]

Hi everyone, 

 

Please bare with me I'm new to this forum. I have done a full service on my audi a4 avant 2017 today however I felt stumped when doing the glow plugs. In cylinder 3 it had a pressure sensor in there? How often does this need to be changed my car is mainly a. Motorway vechicle and is at 98k this is the first time doing it myself normally have Audi do it but I've recently learned theyve done nothing over the years... Going back to the glow plug in cylinder 3 I pulled the sensor out but I hadn't seen anything like this before so I put it all back together. I cant find anywhere to but like eurocarparts.com / gsfcarparts. 

 

Please could anyone advise me? 

 

Regards,