Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number K4B4B found under Shaft Shouldered by Pentair Pump Group Inc. The National Stock Number assigned to this part is 3040011810146, and the Federal Supply Class is 3040 Miscellaneous Power Transmission Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like K4B4B.