Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number HPF-220 PLUS OPTION 2 found under Tracking Filter Con by Integra Microwave. The National Stock Number assigned to this part is 4935013111739, and the Federal Supply Class is . Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like HPF-220 PLUS OPTION 2.