Viair 90150 0-200 PSI Air Pressure Regulator Regulate air pressure at any point between 0 PSI and 200 PSI Locking adjustment dial Mounting bracket included Includes the following brass fittings - T-fitting (1/4 inch NPT female x 1/4 inch NPT female x 1/4 inch NPT male), compression fitting for 1/4 inch air line, 1/4 inch NPT Plug Great for adjusting pressure for air locking differentials