From CarlMartin:

The Carl Martin Compressor/Limiter is a professional-grade dynamics processor pedal designed to deliver the same sonic clarity, quietness, and performance as high-end studio compressor/limiters with built-in power supply.

• Studio-Grade Performance - Engineered to match the features and sonic quality of professional studio compressor/limiters with exceptional 105dB signal-to-noise ratio and only 0.05% THD distortion, delivering ultra-quiet, transparent compression previously unavailable in pedal format
• Versatile Dynamics Control - Four interactive controls provide everything from subtle tone fattening to extreme singing sustain: Threshold (60dB range) sets compression start point, Compression adjusts ratio (1:1 to ∞:1), Response (12.5ms to 125ms) determines attack/release characteristics from fast peak-limiting to active signal-dependent compression
• Visual Compression Monitoring - "Busy Light" LED indicator shows real-time compression activity even in bypass mode, brightening proportionally to the amount of gain reduction being applied for instant visual feedback of your dynamics processing
• Built-In Power Supply - Units after January 2016 feature innovative Carl Martin DC/DC circuitry delivering internally regulated ±12V from external 9V DC supply (130mA minimum), ensuring consistent professional performance without battery hassles
• Make-Up Gain Control - Dedicated Gain knob provides ±20dB range to compensate for compression level reduction or add boost for solos, allowing seamless integration with your clean signal or enhanced volume for lead passages

This pedal is in excellent condition and has been thoroughly inspected and tested by our expert tech.