Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 4053B found under Microcircuit Digital by National Semiconductor Corp. The National Stock Number assigned to this part is 5962011483381, and the Federal Supply Class is 5962 Microcircuits Electronic. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 4053B.