Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number S1-53 found under Cup Pump Blackhawk by Enerpac Corporation. The National Stock Number assigned to this part is 5120004245722, and the Federal Supply Class is 5120 Hand Tools Nonedged Nonpowered. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like S1-53.