This air brake check valve fits Mack, Navistar, and Volvo applications and is sold one per pack. It installs in the air line to allow flow in a single direction, guarding compressors and air system components from reverse pressure. It falls under the Air Brake Parts category for check valves.Interchanges:Volvo 72803-0002Mack 745-227871Mack 745-276421Mack 745-288048Mack 745-800372Navistar 1676699C1Volvo 644916-ALCV-4064FeaturesCategory: Air Brake Parts, Check ValveSell pack: 1 EACHTech SpecsSell pack: 1 EACHUPC: 193807211820