A group of four transducers are placed on the face of the bridge beneath the four strings of the bass, and a Bass Max transducer is inserted into the E or G side wing of your bridge. It terminates to a stereo (3 conductor) jack; a high quality stereo cable is included, to plug into the companion, dual channel preamplifier. For more info: http://www.kksound.com/bassmaster.html http://www.urbbob.com/bmaster.html List price is $380. Bob Gollihur's price is $237. I am asking $175.