Shure Beta 91A, Condenser boundary microphone, Combination of Beta 91 and SM 91, Switchable frequency range for bass drums or piano/ voice applications, Polar pattern: half cardioid, Frequency range: 20 - 20,000 Hz, Impedance: 146 Ω, 11-52 V Phantom power, SPL: 155 dB SPL max (@ 2500 Ohm), Sensitivity: -48.5 dBV/Pa, Output: XLR-male, Weight: 470 g