Features: This product is made of high-quality materials, which is durable and has good effect. It is suitable for various occasions where the acoustic guitar is required to be placed outside the sound. There is a bridge piezo transducer pickup input and C-Mic input, which can highly restores the sound of the guitar resonance in the resonance box. There is a PHASE button that will put the pickup "out of phase" with the speaker. Powered by a 9V alkaline battery (not included), the replacement battery can be used for over 1000 hours. C-Mic can receive the sound of tapping the guitar panel. With it, you can tap the rhythm with a guitar. Specification: Color: Black Material: Metal, Plastic Input Impedance: 22 MegaOhms Frequency Response: 20Hz ~ 20KHz Power Supply: DC 9V, Alkaline Battery (Not Included) Battery Life: Over 1000 Hours Pickup: Omega-II (Piezo Cable Pickup) Output Jack: 6.35mm (1/4") Dimension of the Preamp: Approx. 7.2cm x 5cm x 2cm (Approx. 2.8" x 2.0" x 0.8") Weight: Approx. 91g Package List: 1 x Preamp Box 1 x Piezo Cable Pickup 1 x Battery Case 1 x Battery Cable 1 x Paste Sheet 2 x Cable Clip 1 x User Manual