Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 3504 found under Adapter Straight Pi by Dixon Valve And Coupling Co. The National Stock Number assigned to this part is 4730008379129, 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 3504.