Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 23A-2779SYM55 found under O Ring by Mc Farland Pump Co Llc. The National Stock Number assigned to this part is 5331012197930, and the Federal Supply Class is . Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 23A-2779SYM55.