This height control valve is a replacement for Hendrickson air suspension systems, also fitting Mack applications. Mounted between the frame and axle, it manages airbag pressure by adding or releasing air to keep ride height steady as loads change. It is sold individually for suspension service work.Interchanges:Hendrickson 59935Hendrickson 59935-000Mack 4000-59935000750727FeaturesHeight control valveSold pack of 1 eachSuspension system applicationTech SpecsSell Pack: 1 Each