Manufacturer: Mack • Year: 1990-1993 • Make: MH (refuse) • Model: MH • OEM No.: 221RD312 Manufacturer: Mack • Year: 1990-1997 • Make: All other models • Model: All models • OEM No.: 221RD333 Manufacturer: Mack • Year:Diameter: 3" (76.2mm) Fuse/Pressure: Press Relief Valve/Fusible Plug Glass: Top Height: 9 1/16” (230mm) Inlet: 5/8-18 Outlet: 5/8-18 1993-2006 • Make: MR (refuse) • Model: MR