didi Volume Adjuster Made in Japan

This is a mute for the flute. I used it for practicing in my apartment but no longer need it, so I am offering it for sale.
It is also said to be able to amplify the sound, so perhaps it would be useful for those who are concerned about their sound being too quiet in ensembles?
I used it with Muramatsu and Altus flutes.

Aihara Flute didi type1

Flute Volume Adjuster (Loud/Mute)
VOLUME ADJUSTER - didi
(Volume Adjuster Didi)
List Price: ¥18,000
Made of ABS resin

If you are willing to accept shipping via Letter Pack Plus, I can offer a ¥200 discount.

Thank you for your consideration.