Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 4F21016-187A found under Floor Aircraft by Cpi Aerostructures Inc. The National Stock Number assigned to this part is 1560004389321, and the Federal Supply Class is 1560 Airframe Structural Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 4F21016-187A.