Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 820520 found under Seat Spring by Messier Dowty. The National Stock Number assigned to this part is 1650004533026, and the Federal Supply Class is 1650 Aircraft Hydraulic Vacuum And De-Icing System Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 820520.