BWT Bestmax Pressure Regulators will fit inline with the BWT water treatment system. This inline pressure reducer can be used to reduce incoming pressure to your espresso machine or BWT water filtration system – between 2 – 8 bar. Adjustment is easy by pulling out the ribbed turn dial outward from the base, turning the ribbed dial, and then pushing it back in to lock the setting The included female 3/8″ BSPP fitting so it can attached directly to your BWT Bestmax filter head. The included male 3/8″ BSPP fitting so it can attached directly to your espresso machine hose, usually female 3/8th BSPP. Also included is a maximum 10 bar gauge to monitor inline water pressure so the valve can be manually adjusted, as needed. Most espresso machines need the water line pressure reduced between 35 and 40 psi (~2.5 bar) to operate correctly, and some are as low as 22-24 psi. Too high of a water line pressure can degrade the pump and make the pump squeal. High water line pressure can also force the boilers to overfill and leak. Each pressure reducer ships with the following items include: 1 x pressure reduction valve 1 x 10 Bar scaledpressure gauge and gasket 1 x M 3/8″ BSPP fitting and gasket 1 x F 3/8″ BSPP fitting and gasket For use with water line pressure of 70psi or less. Assembly required.