Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number A1-9258 found under Tool Recondenser by Mks Instruments Inc. The National Stock Number assigned to this part is 3655008441007, and the Federal Supply Class is 3655 Gas Generating And Dispensing Systems Fixed Or Mobile. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like A1-9258.