Broughton Audio, a Canadian boutique pedal maker, is not very well-known in Japan! This is rare equipment in Japan, obtained through personal import. It's a filter effect unit that allows adjustment of high-pass, mid-EQ, and low-pass filters. I used it indoors for about a month. Operation has been confirmed, and there are no issues. It's in excellent condition with no noticeable scratches or stains. - Brand: Broughton Audio - Model Name: Resonant Filter Equalizer - Functions: High-pass, Mid-EQ, Low-pass filter - Power: 9-24V DC Here's an excerpt from Broughton Audio's website description: The Resonant Filter Equalizer combines high-pass, low-pass, and mid-EQ to achieve unique tone control. Both filters each have their own resonance control, allowing for a bump at the cutoff frequency, making the filter's effect stand out. The semi-parametric mid has variable frequency control. The filter resonance ranges from -3dB to +15dB. The -3dB setting is what you would expect from a standard non-resonant filter. Adding resonance to the filter boosts the level at the cutoff frequency. Thank you for looking.