I just bought it, and it's unused. Features The CSB1 is an in-line microphone booster that uses phantom power to amplify the signal level of passive microphones by +26dB. When sufficient gain cannot be obtained with the microphone alone, the CSB1 can cleanly amplify the signal without increasing noise or distortion. Specifications ■ Features ・Amplifies microphone signal by +26dB ・Ideal for low-gain microphones such as dynamic microphones and passive ribbon microphones ・Clean and stable gain with low noise and low distortion ・Slim and compact design with a robust metal housing ・Powered by +48V phantom power ■ Specifications ・Frequency Response: 20Hz～20kHz (-0.3dB) ・Gain: 26dB ・Maximum Output Level (0.5% THD): 10dBu ・Output Noise: -97dBu (A-weighted) ・Power: +48V phantom power ・Impedance: 130Ω ・Recommended Load Impedance: >1kΩ ・Current Consumption: 2.5mA ・Connections: XLR 3-pin ・Dimensions: 19mm (diameter) x 98mm (length) ・Weight: 60g