Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 99K4B-C ITEM 37 found under Pin Diffusor Pump by Pentair Pump Group Inc. The National Stock Number assigned to this part is 5315010503540, and the Federal Supply Class is 5315 Nails Machine Keys And Pins. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 99K4B-C ITEM 37.