The MD 409 U 3 is a dynamic microphone, especially suited for use with percussion and brass instruments. The following text is from Sennheiser publication 18588/A 02, which is dated May, 1986. Undistorted transmission of powerful instruments and instrument amplifiers due to large surface membrane/ Extremely good feedback protection due to pronounced directional characteristics/ Good acoustical separation of the individual instruments, e. g. when recording percussion/ Insensitive to handling noise due to shock-mounted system/ Sound inlet basket made from stainless steel, therefore very robust/ Needs only a little space due to flat, rectangular design/ Genuine gold-plated sound inlet/ Unbreakable quick release clamp