Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 491-004 found under Adapter Straight Pi by Dorman Products Inc. The National Stock Number assigned to this part is 4730014070872, 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 491-004.