Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number M3838-2570 PC NO.12 found under O Ring by Derbyshire Mack And Morgan Inc. The National Stock Number assigned to this part is 5331001651941, 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 M3838-2570 PC NO.12.