This spool insert fits inside the MV-2 dash valve module cartridge used in Mack and Navistar air brake systems, sliding within the valve bore to open or block air ports and direct flow through the circuit. It is sold as each.Interchanges:Mack 745-101570Navistar 576028C91LSP-1199FeaturesUsed in MV-2 dash valve module cartridgeSold as eachAir brake componentTech SpecsApplication: MV-2 Dash Valve Module CartridgeSell Pack: 1 Each