1. strong power: our balls power is over 5200 guass, while others are only 4200--4500 guass.

2. exact size tolerance: our size tolerance is only /-0.02mm, while others are much bigger than this.

3. perfect surface: Our balls surface is smooth and shinning like a mirror, while others are not.

4. quickest delivery time: as we make at least 15000 sets per day, so for any qty, we can send it at once. While others can not.

5. lowest price: Even our quality is the best, while we sell ...