Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 28504-1 found under Pinion by Triumph Controls Llc. The National Stock Number assigned to this part is 3020010600783, and the Federal Supply Class is 3020 Gear Pulley Sprocket And Transmission Chain. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 28504-1.