Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 20340 found under Cylinder Assembly A by Boeing Company The. The National Stock Number assigned to this part is 1650013887823, 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 20340.