Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 57K8475 found under Armor Setsupplementalsmall Arm by Ibis Tek Llc. The National Stock Number assigned to this part is 2541016816955, and the Federal Supply Class is . Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 57K8475.