Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 337 1688 03 found under Cover Access by Tektronix Inc. The National Stock Number assigned to this part is 5340011460638, and the Federal Supply Class is 5340 Hardware Commercial. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 337 1688 03.