Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 3921 found under Coupling Half Quick Disconnect by Tuthill Corp. The National Stock Number assigned to this part is 4730002937167, 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 3921.