NHRA regulations require that any nitrous bottle mounted inside the cockpit (including the trunk) of a vehicle to have a blow down tube to evacuate the nitrous out of the vehicle. This blow down tube connects to the NHRA fitting on the bottle valve.
00-35041-B-S Nitrous Outlet 90 Blow Down Kit With Straight Bulk Head Fitting
Nitrous Outlet 90 Degree Blow Down Tube
00-40502 Nitrous Outlet 1/8" NPT Dry Nitrous Nozzle 90 Degree Discharge 500 HP
Nitrous Outlet 1/8" NPT, 90 Degree Wet Nitrous Nozzle
00-40003 Nitrous Outlet 1/16" NPT 90 Extended Reach Wet Nitrous Nozzle
00-40001 Nitrous Outlet 1/16" NPT 90 Degree Wet Nitrous Fogger Nozzle