The use of hard and stable materials as a material for audio is significant, thus Nagaoka have developed an audio insulator that combines ruby balls and metal.

• Ruby is a single crystal material with hardness second to diamond, and the effect of suppressing resonance and separating vibrations between insulators is enhanced.
• Ruby + brass improves rich sound and clearness, resolution, and localization while maintaining the balance of the band.
• Stainless steel and brass are scraped out with a NC processing machine by computer control and the product is assembled at Nagaoka's factory.
• When the product is installed, a part of the ruby material is visible, but the color changes in the way it hits the light, giving an even more luxurious feeling by the contrast between metallic luster and ruby luster.