Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 427508(SZR-1 found under Sight Bore Optical by Vectronix Inc. The National Stock Number assigned to this part is 1240013647514, 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 427508(SZR-1.