Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number SM-B-544277 found under Shield Microphone by Sonetics Corporation. The National Stock Number assigned to this part is 5965009336894, 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 SM-B-544277.