Blowdown tube ?
It's smart to have for general safety. If you have a blowout in the car, the sulfur they add to the N2O will bug the crap out of your lungs. I don't know what kind of car you have, but I'm pretty sure you only need a blowdown tube if the bottle is mounted in the passenger ( which in an F-body is the whole interior--unless you have a rear firewall)



