What is this canister in my engine compartment '08 4R v6

[Seymore Butts]

And does it ever need to be serviced?

<a href="https://imgur.com/DpLbyAg"><img src="https://i.imgur.com/DpLbyAg.jpg" title="source: imgur.com" /></a>

 

[FortCollinsT4R]

I’m not 100% sure on this, as I have a V8, but I believe that is either the one way valve to the brake booster or a valve for the evap system. Never heard of them needing serviced unless there is a problem with it sticking closed/open.