Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 21A18-04C42-6 found under Hose Air Duct by Meggitt Oregon Inc. The National Stock Number assigned to this part is 4720016056060, and the Federal Supply Class is 4720 Hose And Flexible Tubing. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 21A18-04C42-6.