Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number RR-S-720 found under Stepladder by Federal Specifications. The National Stock Number assigned to this part is 5440000618898, and the Federal Supply Class is 5440 Scaffolding Equipment And Concrete Forms. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like RR-S-720.