All ports are 1/8NPT. Original equipment on many Trucks and Trailers Automatically adds air to or exhausts air from air suspension to maintain constant static design height Does not respond to short duration dynamic changes in axle position thus reducing air consumption which extends compressor life and saves fuel | Haldex Controlled Response CR Height Control Valve 1/8 in.

Haldex 90054007 Height Control Valve
$48.59