Bang and Olufsen B&O Fen-tone 53 BM4 blue-ribbon velocity microphone – Retro Gear Shop
Cole Picks Vintage on Instagram: "Bang and Olufsen BM3 - $450 Each - Here's a Bang and Olufsen BM3 Ribbon Microphone from the 1960's! B&O made ribbon and dynamic microphones out of
Xaudia Microphone Blog: The Bang and Olufsen ribbon microphone family