Behringer 4-channel expander/gate, the XR4400. There are a few scratches on the top of the product. Power-on check only. Accessories include the power cord only. Quoted below: (The BEHRINGER/XR4400 is a 4-channel expander/gate ideal for noise reduction during recording and auto-mute control of microphones. Each channel is equipped with a switchable expander/gate and a sidechain filter that can narrow the operating frequency band. It is ideal for recording drums using multiple microphones.)