Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 803-6915566-20. 5 found under O Ring by Gw Technologies Pty Ltd. The National Stock Number assigned to this part is 5331000200186, 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 803-6915566-20. 5.