Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 4789B found under Elbow Pipe To Tube by Dresser Rand Co. The National Stock Number assigned to this part is 4730008778997, 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 4789B.