Blow down tube

[North Cali Autocrosser]

Does the bottle have to be empty to put this on, is it a new fitting that goes on?

[Skinny]

Yes, there's a different pop off cap that goes on there. If you already have the "safety popoff cap" then it should have threads on the outside of it for the blow down tube. That at least goes for the newer style bottles.

[12secondv6]

Yup, if the bottle does not come with it then you need to completely empty a bottle and screw a new fitting in the side of the main silver unit.
Then screw the blow down tube right onto that

[North Cali Autocrosser]

Thanks. :D