This height control valve mounts between the frame and axle on Hendrickson air-sprung suspensions, adding or releasing air to hold ride height steady as loads change. It is a replacement suited to Hendrickson and Mack applications. Sold individually.Interchanges:59935-3Hendrickson 59935-003Mack 4000-59935003750729FeaturesHeight control valve for air suspension systemsSold pack quantity: 1 eachTech SpecsSell Pack: 1 Each