Royer Labs dBooster, In-Line Signal Amplifier, For ribbon and dynamic microphones, Switchable gain (12/20 dB), Frequency range: 20 to 20000 Hz, 48 V Phantom power supply, Class-A input stage, High-impedance XLR input and low-impedance XLR output XLR, Dimensions (W x H x D): 51 x 41.3 x 92 mm, Weight: 170 g