This is the new BallBearing as comes standard with the new YoYoFactory plastics in Size A. Now available as replacement for any Yo-Yo that uses the Size A Bearing.
The Dif-e-Yo KonKave Stainless Bearing centers the string while at the same time allowing it to move when needed for response. Size A (5x10x4 mm). For all Duncan Yo-Yos, YoYoFactory...