FISHMAN PRO-MAT-NFV ACTIVE PICKUP SYSTEM WIDE - Features the Acoustic Matrix, the Best Selling Undersaddle Pickup - Excellent for Acoustic Steel-String, Nylon, and Bass - Feedback Resistant - Includes Volume, Tone, and Voicing Control - A redesigned, sealed enclosure for the soundhole-mounted Volume and Tone control module allow players to effortlessly make adjustments to their sound. The preamp’s voicing switch has been relocated and made easily accessible so players can accommodate different types of guitars, amplification choices, playing styles and performance situations. Professional Installation Recommended.