LR BAGGS M1-A SOUNDHOLE PICKUP - The M1 Active’s plug-and-play design features a preamp with audiophile circuitry for that pure acoustic sound. The built-in electronics boosts the pickup’s output for a full and direct signal to any acoustic amplifier or P.A. system, eliminating the need for any external preamps. The M1 Active includes a volume control and adjustable pole pieces for perfect balance and tone between the strings - Highly Feedback-resistant - Volume control - Built-in gold plated 1/8" jack makes removing the pickup a snap - Long battery life – 1,000 hours on one 3V lithium coin cell - Quiet hum-free operation -  Professional Installation Recommended... we do that -