USA-NX-ML15600 - The Mainline Purge System is designed to purge the air from your nitrous lines to allow immediate activation of your Nitrous system. This System includes a stainless steel purge solenoid, push button for activation, and a vent tube to direct the purged nitrous out of the solenoid. Also included is a -4 AN manifold to run inline with your nitrous feedline. This allows you to purge the nitrous system, even when you do not have a purge port built into your solenoids. The Purge system can also be used to lower the bottle pressure for spot on nitrous performance every time you activate the system. Purge System includes: Purge Solenoid. 4 AN adapter manifold. Push button activation. 1/8 to 1/8 NPT Fitting. 1/8 NPT to Compression Fitting. 7 inches of 3/16" Stainless Tubing.