The switch is true bypass. Purchased a custom-made pedal about 25 years ago from a professional shop. - Boost function added → Overdrive feel can be adjusted with the knob on the back of the pedal. - IN/OUT jacks consolidated on the left side. - External battery. No noticeable dirt or scratches. VOX Wah pedals are essential items for adding a wide range of expression to your guitar sound. - Brand: VOX - Model Name: Vox Wah Pedal - Accessories: Instruction manual, dedicated case - Terminals: IN, OUT - Adjustment Knob: Treble adjustment knob Thank you for viewing.