Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number S1635-64041 found under Window Observation by Sikorsky Aircraft Corporation. The National Stock Number assigned to this part is 9330003083535, and the Federal Supply Class is 9330 Plastics Fabricated Materials. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like S1635-64041.