in standard Lectrosonics frequency blocks. Ultra low noise op-amp ensures quiet operation and high headroom. Phantom power is selectable for 5, 15 and 48V for condenser and electret condenser microphones. The locking collar prevents the unit from accidentally falling off the microphone and the input gain is adjustable over a 43dB, allowing flexible impedance matching. The unit is powered by a single 9V battery and provides a full 100mW output over the life of the battery.