This is from when I used to play guitar in a band, a long time ago. It's old. Operation has been confirmed with both a battery and an adapter. ◆BOSS/GE-6/Graphic Equalizer/Made in 1979/Made in Japan◆ The first graphic equalizer compact pedal released in 1978. It was succeeded by the GE-7 in 1981, making it a short-lived model with a production run of only three years. This unit is from 1979, features silver screws, and is equipped with two μPC4741C op-amps. ●No accessories (body only)