No operational issues. The knob has been replaced (the original is not included). Only the main unit will be provided. Please note that price reductions are not possible. Compression, clean boost/gain boost, and mid-range sound adjustment. All of these are possible with this completely new concept pedal that allows for intuitive control. The knobs are compression, level, gain, color1, and color2. The compression function follows the Limetone Audio compressor pedal, focus, and achieves studio-quality compression with simple operation. You can intuitively understand the compression status by the timing of the LED lighting, the intensity of the light, and the timing of the light going out. The level and gain knobs are located after the compression stage, allowing for clean boost with level and gain boost with gain. Especially for gain boost, the tone curve is set to be optimal for pushing the distortion of subsequent pedals/amps, allowing you to create a powerful drive sound. Color1 and color2 are both knobs that operate in the mid-range, with the 12 o'clock position being flat. By boosting and cutting a limited range that cannot be operated with amps or regular effectors, you can create and refine sounds that were previously impossible to set. Also, as a feature of FOCUS-NX, turning either color1 or 2 to 3 o'clock or higher can produce a mid-range-characteristic sound. Color1 is a slightly higher frequency, and color2 is a slightly lower frequency. Turning color1 up to near the maximum value results in a modern sound, and turning color2 up results in a sound like an old-fashioned half-cocked wah. (It is assumed that only one of them is raised, but it is also possible to create a more aggressive sound by raising both.) Each function (compressor, booster, mid-tone shifter) can be selected to be used or not used by setting the knobs, and each function can be used individually or in combination.