Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number E40-42X58 found under by Unisource Worldwide Inc. The National Stock Number assigned to this part is 9310010773609, and the Federal Supply Class is 9310 Paper And Paperboard. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like E40-42X58.