Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number PKA-50B-1-4 found under Knob by Alco Industries Inc. The National Stock Number assigned to this part is 5355010479501, and the Federal Supply Class is 5355 Knobs And Pointers. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like PKA-50B-1-4.