Vintage Boss CS-1 Compressor (Long dash, silver screw) in excellent condition for its age! This is the first Compression/Sustainer pedal released from Boss. It builds on the lagacy of the Roland AS-1. Like all compression pedals it reduces the output of sounds over a set threshold relative to the strength of the input signal, making levels consistent and improving sustain. Message me for current international shipping rates. All products guaranteed. 14 day return policy.