This is a used Retro Instruments 176 valve compressor.
The Retro Instruments 176 is based on a Bill Putnam classic, the UA 176. The 176 faithfully reproduces the sound of the 1960s original with new features for the modern recording studio. The Retro Instruments 176 provides one of the most desirable compression signatures in recording history.
This particular used Retro 176 is in excellent condition, and has just been fully serviced.