Using CLASS-A amplifier circuit design, with high-order transistor MP5+, lower audio output impedance, and stronger load capacity.Simple connection, plug and play: just plug the microphone amplifier into the microphone's XLR output port. The sound card + microphone amplifier can provide 28DB of pure gain, which is equivalent to directly increasing the sound card microphone amplifier by 28DB without affecting the sound quality. Instead, it can reduce the noise problem caused by excessive gain of the sound card itself. The professional microphone enhancer is an active embedded preamplifier that is inserted between the preamplifiers of passive ribbon or dynamic microphones. Built-in lithium battery, 5 hours of battery life, no additional power supply required. Press the amplifier switch, and the power-on light turns red, and the amplifier can be used. When charging, the charging indicator light turns red, and when fully , the charging indicator light turns green. Applicable equipment: Applicable to speakers, sound cards, mixers, amplifiers and telephones. Frequency range: 10-120,000 Hz (-0.,3 dB) Gain: 28 dB (load 1kohms) Maximum output level (0.5%): 8.3 dBV (2.6 V) Output noise: 9 V (-A) Power supply: built-in lithium battery, 5V charging Resistance: 135 0hms Load resistance: 1k 0hms Power consumption: 3.0 mA Connection: 3-pin male/female XLR connector The buttons on the amplifier may have random colors from batch to batch,can not be chosen the specific ; the silk screen printing may be different from batch to batch, but it will not affect the use Colour:Black Material:Aluminum Alloy Package Contents: 1 x Microphone Amplifier Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.