Jam Pedals Dyna-ssoR Electric-Bass Effect, Compressor/Sustainer, based on the original Ross Compressor and the DynaComp., mit Regler for Controls for Level, Sustain (compression), True Bypass, works with Battery 9V or power supply 9V DC, (not included) (Optional Power supply 108096), Each Pedal is hand painted individually and is therefore one of a kind. Due to this, variations can occur.