Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number PN5-1IN found under Coupler Scaffolding by Hollaender Manufacturing Co The. The National Stock Number assigned to this part is 5440011550271, 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 PN5-1IN.