Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 28-90270PC4 found under Packing Preformed by Treadwell Corporation. The National Stock Number assigned to this part is 5330011321920, and the Federal Supply Class is 5330 Packing And Gasket Materials. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 28-90270PC4.