This is a used Midas 522 V2 API Format 500 Series Compressor, a single-channel analogue compressor designed for professional audio applications. It features compression and limiting effects, providing a high-quality sound processing capability for your audio signals. With its API format, this compressor is compatible with other API 500 series modules, allowing for easy integration into your existing setup. This unit is ideal for musicians, producers, and audio engineers looking to enhance their sound with precision compression.