Thank you for viewing. This is the HANABUSA Pianissimo Mute. It's a beautiful item, only used for testing. The following is an explanation from the official website: A mute that allows you to play the ultimate pianissimo without losing the tone of the mute. The response is good, and you shouldn't have to worry about resistance or changes in pitch. With courage, This is the mute I recommend you choose when you want to express your desired pp. Personally, the sound produced is quite small, but the playing feel remains the same, and it produces a mute-like sound, which I think can be used in those crucial moments! Thank you.