BOSS GP-20 Guitar Amplifier Processor - Junk This item is being sold as is. It has been lightly cleaned, but there is a malfunction where the sound cuts in and out. Sound is produced when the effects are off, but it cuts out frequently when they are on. Please be aware of this and only purchase if you are able to repair it or need it for parts. The adapter is not included; only the main unit is included, so please be careful. There are some scratches and stains. Instant purchase is OK. Thank you. Guitar Amplifier Processor that realizes a variety of tones - Model: GP-20 - Function: Guitar Amplifier Processor - Controls: Volume, Treble, Middle, Bass, Presence, Master - Switches: Memory, Write, On/Off - Country of Manufacture: Taiwan - Serial Number: Z020649 - Connection Terminals: Output Terminals, Speaker Cabinet Terminals Thank you for viewing.