Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 194-4 found under Liner Cylinder by Donallco Inc. The National Stock Number assigned to this part is 1650001823473, 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 194-4.