Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 306-85-21 found under Cap Air Cleaner Intake Pipe by R Cushman And Associatesinc. The National Stock Number assigned to this part is 4310015433639, and the Federal Supply Class is 4310 Compressors And Vacuum Pumps. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 306-85-21.