Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number PI 3502-12-852-125 ITEM 3 found under O Ring by Siemens Energy And Automation Inc. The National Stock Number assigned to this part is 5331012945277, 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 PI 3502-12-852-125 ITEM 3.