Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number MF504-DBB found under Motor Hydraulic by Spencer Industries Inc. The National Stock Number assigned to this part is 4320012746790, and the Federal Supply Class is 4320 Power And Hand Pumps. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like MF504-DBB.