Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number E863 found under Valve Box by Mueller Co. The National Stock Number assigned to this part is 4730005230434, and the Federal Supply Class is 4730 Hose Pipe Tube Lubrication And Railing Fittings. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like E863.