This is a screw for Jupiter and Schilke, produced in small quantities in response to a customer request.
 It is made of phosphor bronze, which increases its volume considerably, and is then layered with silver and gold plating.
 It seems to be able to flexibly respond to a wide range of sounds, from soft, blending sounds to crisp, dignified sounds.
 The genuine products are made of brass or nickel silver, so this product is slightly darker in comparison.
 How about an affordable modification?