Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 755A found under Sound Controlling Board by Armstrong World Industries Inc. The National Stock Number assigned to this part is 5640003145972, and the Federal Supply Class is 5640 Wallboard Building Paper And Thermal Insulation Materials. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 755A.