Sensitive microphones, while recording loud sounds can overload a recorders microphone pre-amp stage causing distortion! You would then use the microphone(s) to feed the line inputs, however some units don't have line inputs (camcorders, some analog recorders, older equipment) You would simply put the attenuator cable (20 dB) in line from your recorder to your microphone(s) effectively, preventing overloading! The (MM-AT-1) is approx. 13 " long constructed of high quality, double shielded, flexible microphone cable. At each end of the cable is 1/8 " gold plated mini-plug (male) to a 1/8 " gold plated (female) mini- jack.