This is very useful when looking for an upgrade for many of the metal Yo-Yos being released. Usually, you will only need the Bearing, and nothing else when upgrading to Dif-e-Yo's KonKave Bearing.
The first Dif-e-Yo's had Grooved Bearings to center the string. As the gap in Yo-Yos became wider for more advanced play, a better "playing" bearing was needed because the grooved Bearing trapped the string in the center while additional string layers moved to the sides of the Yo-Yo slowing it down.
The KonKave Bearing is designed for Smoother multi-layer string tricks with longer spin times. Not only does it help keep the string centered... it also forces additional string layers to the center and away from the sides of the Yo-Yo.
Whether you are a Beginner or Advanced player... With a Dif-e-Yo KonKave Bearing you will experience a smoother and more predictable playing Yo-Yo.