Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 820-4384426 IT.5 found under Diaphragm by Mcdermott Inc. The National Stock Number assigned to this part is 4470009950693, 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 820-4384426 IT.5.