The Barcus-Berry Piano and Harp Pickups reproduce the instrument's full frequency range with perfect amplitude balance. It provides excellent isolation from ambient sounds - with superior feedback rejection. It suppresses amplification of keyboard and pedal noise on a piano and is quick to set up with no holes to drill or tools required .A single Planar Wave System does the job that would otherwise take several microphones and a multi-channel mixer to achieve. Best yet, it attaches easily to either side of the soundboard without holes to drill or tools. Features include active direct box which includes a 9-volt battery or phantom power, 1/4" monitor output with variable level, balanced, XLR main out with ground lift and output pad switch. Includes piezo crystal from piano. Specifications: Piezo Buffer Preamp. Input: Input Interface: 1/4" Unbalanced. Input Impedance: 2.2 Meg Ohms. Maximum Input Leve: 2.0 vrms. Monitor Output: Output Interface: 1/4" Unbalanced. Output Impedance: 2K Ohms. THD: .005% @ 1kHz. Noise: -102dBu. S/N: 110dBu. Frequency Response: 5Hz - 30kHz (+/- 1dB). Main Output (0dB Setting): Output Interface: XLR Balanced. Output Impedance: 1K Ohms. THD: .005% @ 1kHz. Noise: -105dBu. S/N: 108dB. Frequency Response: 5Hz - 30kHz (+/- 1dB). Power Supply: Phantom Power or 9v Battery. Power Source: 9 Volts @ 380 Microamps. Battery Life: Approximately 1,000 hours.