Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 438644SP found under Shield Microphone by Helmet Integrated Systems Ltd. The National Stock Number assigned to this part is 5965016202526, and the Federal Supply Class is 5965 Headsets Handsets Microphones And Speakers. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 438644SP.