This is a 10mm endpin socket made by Berdani of Germany. The body is made of ebony. The black rod in the photo was attached as a test for fixing the screw and is not included with the product. I purchased this but was unable to use it because the size did not fit the hole in my instrument, so I am selling it. Normal endpin sockets fix the endpin with a single screw, but this item has a structure that holds it down with a wide ring-shaped part. (This is similar to the picture from Sasaki Violin Workshop: https://www.sasakivn.com/werkstatt/qa/stachelwechsel2.gif) The socket has a diagonal taper, but the maximum diameter of the part to be inserted into the instrument is 25mm (measured with calipers). Although this is a common size socket, please note that it cannot be installed if the hole diameter on the cello side is different. I use the same type of endpin socket, and it has the following features: ・The pressure on the endpin is reduced, and the surface of the rod is less likely to be scratched. ・Perhaps because the endpin is held down over a surface rather than a point, it feels more stable, and the sound quality becomes more solid. As you can see in the photo, there are some slight chips, but I believe they were made during production. That's all. Thank you.