This is a set including the main unit, calibration microphone, remote control, and power cable. I have confirmed that sound is output from all coaxial inputs and all analog inputs (I only checked if the PHONO input produced sound because I don't have a record player). I have confirmed that speaker output works fine for each input, and that speaker calibration also works. For headphones, I confirmed sound output from coaxial input 1. The remote control also seems to be working fine. Regarding the bass equalizer, there was only one time previously when it was occasionally slow to respond if turned clockwise quickly, but I have since checked it and it is working without any particular problems. Therefore, I believe there are basically no operational issues. The volume and other switches seem to be working fine. The sticker on the top panel has been removed, but I don't think there are any noticeable scratches. Even if a problem occurs, you can operate it with the remote control instead of the knobs on the main unit.