Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number LSC 8504 PART7 2.50 IN found under O Ring by William E Williams Valve Corp. The National Stock Number assigned to this part is 5331014549979, 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 LSC 8504 PART7 2.50 IN.