DOD Compressor 280

They say:

The 280 is an optical compressor that can go from light sustain to utterly smashed with the turn of a knob. The Comp knob gives you everything from subtle volume leveling to full-on squash. You’ll also appreciate the true-bypass circuitry that keeps your tone pure when the effect is off. DOD also loaded the Compressor 280 with a blue indicator light, a lightweight aluminum chassis, and a modern 9-volt power supply input. Keep your volume and dynamics in check with the DOD Compressor 280 pedal.