From C3YoYoDesign:

World YoYo Contest Champion Sora Ishikawa signature model - "Stellar IX"💫

Sora's signature yoyo "IX" revolutionize the design of the 5A competition yoyo, while the new version "Stellar IX" further enhances performance and durability!

Keep the weight same as IX at 73.5 grams, the diameter and width have been fine-tuned and adjusted to fit for Sora’s request. The diameter reduced 2mm to 62.45mm, and the width is slightly narrowed from 64.1mm to 63.84mm.

The biggest change is the material use of body, new version IX use the PC which available to increases the thickness of body in design, that help to improve the weight distribution of stainless steel ring, and the spin power is greatly enhanced!

Of course, the same as previous version, players can purchase C3 offstring spacer for switching to 4A style setting, enjoy the Innovative Extreme!!!