YAMAHA SILENT Brass ・Personal Studio STX-2 unit ・Genuine earphones (YAMAHA) ・Connection cable (for the mute) ・Instruction manual These are the only four items included. "Brass Resonance Modeling" reproduces the realistic sound of brass instruments. "Brass Resonance Modeling" is Yamaha's unique digital technology that cancels out the muffled sound of a mute and reproduces the original sound without a mute. By combining the Personal Studio STX-2 and a compatible pickup mute, the player can perform while listening to a realistic sound as if they were not using a mute. Operation has been confirmed and it is fully functional. It is in good condition as it has only been used a few times. I am selling it because I haven't used it much. Free shipping. Thank you.