Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number AR5.13.15 IT21 found under O Ring by Kone Industrial Oy. The National Stock Number assigned to this part is 5331014448697, 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 AR5.13.15 IT21.