Fishman M-300 Archtop PRO-M30-0MA; Archtop Mandoline Pickup, Nashville Series with new Piezo-Ceramic Technology, The Bridge/Piezo combination transmits the natural sound of the Mandoline; suited for Archtop Mandolines ; Set includes Carpenter-Style 6.35 mm Jack socket for side mounting on the instrument; a preamp is recommended but not neccesary; professionel Installation is required.