Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 12543-503A found under Cover Kit Duct by Arrowhead Products Corporation. The National Stock Number assigned to this part is 1560014605964, 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 12543-503A.