All-Silver Neck Joint Super Ring GP (for Alto Saxophone) 2mm "Nagasawa Seisakusho" original wind instrument boost item. Compatible Models: Yamaha Various Yanagisawa (T series to current WO) Selmer (Mark VI to Supreme) Can be used if the neck joint diameter is the standard size of approximately 24.5-24.7mm. * A 2mm "24K gold-plated 950 silver ring" is attached to the neck joint of the alto saxophone. It produces a sound with richer overtones than the 1mm version. ☆ Typical characteristics of each surface finish ☆ Pure Silver: Characterized by the soft tone of silver. GP: Characterized by a rich resonance with good articulation. PGP: Characterized by a warm resonance. Effects: Easier to produce altissimo notes. Altissimo notes become fuller. Altissimo notes sound better. In addition, many users have reported improvements in overall resonance and tone stability. Made using the same silver soldering and polishing process as rings. Quantity: 1 ring. Material: 950 Silver Ring inner diameter: 24.5-24.7mm (with some variation). Ring outer diameter: 26.5-26.7mm (with some variation). Uses 2mm x 1mm material. Made to be slightly loose. Please give it a try. At Nagasawa Seisakusho, The creator himself has experience winning international competitions, and based on that experience, they have repeatedly tested and prototyped, and are designing and manufacturing all-silver wind instrument boost items in their workshop in Hatoyama-machi, Hiki-gun, Saitama Prefecture.