The Roland Jazz Chorus 50 is a 50W guitar amplifier with a 12-inch speaker and six control knobs. I received it about 30 years ago and have been using it at home for practice. There are some rust and crackling noises. Please refrain from purchasing if you are sensitive to signs of use. - Model Name: Jazz Chorus 50 - Brand: Roland - Number of Control Knobs: 6 - Speaker Size: 12 inches - Output: 50W The dolly shown in the picture is not included. Thank you for looking.