BOSS GS-10 Guitar Effects System - a legendary piece of equipment. This is a COSM-equipped effects unit with a built-in speaker. It's a convenient multi-effects unit with XLR input, MIDI in/out, USB connection, and a built-in speaker. While there is some aging and signs of use, it's generally in good condition. It functions without any problems. The high-gain sounds are also excellent thanks to COSM. The low-gain overdrive and chorus sounds are also surprisingly good. You can practice at home with headphones. The built-in speaker also has quite good sound quality. You can practice with just this one unit. Includes the original AC adapter. Will be shipped quickly in recycled cardboard and bubble wrap. Thank you.