※ Information regarding price negotiations is listed in my profile. Please take a moment to review it beforehand. This part is designed to be attached to musical instruments to improve sound cohesion and clarify tonal centers. To accommodate a wide range of instruments and attachment points, the adjustable range has been made broad. It is intended for use with mid- to low-range instruments such as trombones, euphoniums, and tubas. The length can be adjusted from a minimum of 75mm to a maximum of approximately 130mm, but I personally think around 120mm is more practical. The central threaded part is 5mm, and the outer diameter is 7mm. The diameter of the disc-shaped part is approximately 13mm. The use of two nuts is to prevent loosening. I believe it can be secured with just one. Regarding the support post, I believe that a fixed, soldered support post, or one with a smaller adjustable range, would be more effective than this product. (Soldering is probably the most effective.) This product does have an effect, but rather than maximizing the performance of the support post, it is primarily designed to allow you to experiment with "how the instrument changes when a support post is added." For this reason, the adjustable range is wide to allow attachment to various instruments and locations. While there should be no issues with use, please be aware that this is a handmade item, and there may be variations in soldering and finish. Also, the finish is not like that of a commercial product, so please understand this beforehand. I have taken and uploaded photos of each item, so please use them to make your judgment. This part is an experimental part and is not intended for use with any specific instrument. I hope you will consider it. This part is also sold elsewhere. We will give priority to the first person to purchase, so please be aware of this.