I used this for practicing musical instruments. I'm selling it because I haven't used it much recently. A plastic part was broken, so I made a replacement part with a 3D printer and repaired it. The holding power of the joints has weakened due to aging. I think it's wear and tear, not broken. It's a clip-on type. Operation has been confirmed, and it works without any problems. There are some minor scratches, so please check the photos.