This item is over 30 years old. Also, since I don't have an environment to test the sound, I can't determine if it's fully functional. However, there's no major damage, so if there's no rust inside, I think it's a product that can be used normally. By the way, I used it for bass. Guyatone L-VI Limiter/Compressor, with adjustable Level, Threshold, Filter, and Attack. - Model: L-VI - Brand: Guyatone - Function: Limiter/Compressor - Controls: Level, Threshold, Filter, Attack - Country of Manufacture: Japan - Battery: 9V battery - Serial Number: 871943 Thank you for viewing.