This is a signature ligature for alto metal mouthpieces, released by Gottsu. It's the "Metal HL Alto" size. The inner diameter, measured from the side without the ligature screw, is 2.5cm. It should fit metal alto mouthpieces and rubber soprano mouthpieces. The material is a copper ring ligature with a hammered finish. The brass screw and the plate that secures the reed are plated with 24-karat gold. It features a moderate resistance due to the copper and the soft tone inherent to copper. It gives the impression of producing a thick, well-rounded sound that adds depth to the performance. I believe it has the potential to be used in genres other than jazz. The ligature body has discolored due to being made of copper, but this does not affect normal use. It has only been used for about a year, so you can enjoy the changes that will occur from now on. It will be shipped in the original box that the ligature came in. Thank you.