Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number PPP-B-621 found under Box Shipping by Federal Specifications. The National Stock Number assigned to this part is 8115000635177, and the Federal Supply Class is 8115 Boxes Cartons And Crates. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like PPP-B-621.