COMPRESSION PEDAL The 280 is an optical compressor that can go from light sustain to full compression just by turning the knob. Unlike faster non-optical circuitry, the 280 preserves high frequencies all the way to the most extreme settings. The 280 is great for chicken-pickin', added sustain for solos, or snappy-slappy funk rhythm. The 280 also has enough output to be used as a boost with compressor sustain. Comp (compression) and Level (volume) controls. True Bypass. Jack In/Out. Blue status LED. 9V battery or optional adapter. Dimensions: 11.9 x 6.7 x 5.7cm. Weight: 281g.