All billet aluminum construction with a unique diaphragm material allows you to use any gas that you can buy from the pump. Fully rebuildable and equipped with a vacuum port to allow it to reduce fuel pressure under high vacuum conditions such as deceleration and idle. On supercharged engines, it is designed to help increase fuel pressure under boost conditions automatically. Adjustable from 30 to 75 psi. 1/8'' NPT gauge port.