Is this a Fuse or a Cap?

[sansan]

Guys help me.

What is that red box?
it has T 3.15A (Ampere???) marking, but also have 392 (3.9nF???) on it.

It is in series on the layout.. Mains layout.
Is it a Fuse?

It's a Laptop charger.

Thanks.

[wraper]

It's a 3.15A fuse. https://www.littelfuse.com/media?resourcetype=datasheets&itemid=9d155b20-d018-47a8-841a-d1aa2fba25d6&filename=littelfuse-fuse-392-datasheet

[sansan]

It's a 3.15A fuse. https://www.littelfuse.com/media?resourcetype=datasheets&itemid=9d155b20-d018-47a8-841a-d1aa2fba25d6&filename=littelfuse-fuse-392-datasheet

Ah, 392 is the series name....
what a confusing naming... 

thanks @wraper

[Haenk]

Not stated is the "T", which stands for "träge" (i.e. "slow blowing") in German. Just in case you are replacing the fuse with another manufacturer.

Edit: That's why that series is called "time lag fuse", I guess

[abdulbadii]

can try google which gives all datasheet sites, so they'd tell us it's hi-V fuse
or can try meter it  which gives continuity to mean it's fuse that haven't blown up

note: to google get the mark having first character is letter or in so rare case a number followed by letter
as whole number would refer only to registration, serial, or date/timestamp number