PRO D2 is a passive DI box: It has 2 unbalanced input interfaces, which are 1/4 inch (6.35mm) interfaces, for connecting musical instruments or other unbalanced signal sources, such as electric guitars, electric basses, keyboards, etc.; and 2 balanced output interfaces, which are XLR interfaces, for connecting mixers, audio interfaces or other devices that require balanced signal input. The input and output are equipped with isolation to isolate ground loop current infection, and also have a 1/4 inch Thru interface to send unprocessed signals to other devices, such as amplifiers , for live monitoring. Frequency response: 20Hz - 20kHz, which can the integrity of the audio signal and that both high and low frequency signals can be transmitted well. Input and output impedance: The input impedance is 50k, and the output impedance is 600, which helps to reduce signal reflection and distortion and effective signal transmission Attenuation (Pad): Used to reduce the level of the input signal to prevent signal overload. The attenuation values are 0dB, -20dB -40dB. Ground Lift: Used to disconnect the Pin1 transmission on the DI box XLR jack to prevent current from flowing along the shield between the DI and the microphone preamplifier, thereby disconnecting the ground loop and eliminating noise such as caused by grounding problems. Applications For acoustic guitars and bass guitars For stereo keyboards and drum machines Connect consumer audio products to professional audio equipment Eliminates "squeaks" and "hums" caused by ground loops Ultra-rugged design for extended life Plug and play for easy operation Completely passive design, no power required Colour:As Shown Material:Metal Tips: The product may be updated constantly ,Due To Different Batches, The Actual Product May Have Slight Differences Or Color Differences, Which Does Not Affect Use Package Contents: 2 * Audio Isolator 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.