Features : Uses MS (Mid-Side) Stereo Sound Pickup System, Pickup the Natural Sound, Transmit Ultra Clear Stereo Sound Quality. Can be Set up According to the Sound Source and Individual be fond of Pickup Pattern (Impact Range Width) to 900 or 1200 Specification: Type : MS (Mid-Side) Stereo Wire Length : About 28cm Power Requirement : 3V CR2 Battery Life : About 800 Hours Size : 30.5*61*132.5mm Performance Parameters : Frequency Response : 30-15000Hz Sensitivity : -40dB ±2dB(0dB=1V/Pa1KHz) Pointing to the Features : Single Directional x 2 Output Impedance : 200Ω Single-to-Noise Ratio : 76dB (1 KHZ at 1PA) The Loudest Level : 120dB at 1 KHZ harmonic distortion 1 percent or less Power Supply : 3V DC.