Anyone know what this part is called

[Sheen]

Anyone know what the part in the white sqaure is called have no idea been searching the Internet to no success any help is greatly appreciated 

[Mark M.]

febi bilstein 48801 Pressure Reservoir for vaccum system

[Magnet]

Hello Sean,

It’s now Wednesday following you joining and posting your request for help on Monday. 
Mark has given you a most helpful reply, but it appears you have not returned to the forum to read, let alone acknowledge, the help you have been given.

Please don’t continue this ‘Post and run’ tactic. 
Regards,

Gareth.