Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number PW055B found under Ring Wearing by E C Schleyer Pump Co Inc. The National Stock Number assigned to this part is 4320002129509, and the Federal Supply Class is 4320 Power And Hand Pumps. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like PW055B.