<0.3mm, it is the smallest size, but the color of bleaching is best. Even the bleaching speed is a bit slow, but the cost is the cheapest.
<0.5mm, it is the middle size, color bleaching also is good. Bleaching speed is fast, but the cost is a bit higher than <0.3mm.
0.3-0.7mm, it is the biggest size, but the color of bleaching might not good as <0.3 and <0.5mm. Bleaching speed is fastest in the three sizes. The cost is the highest.
We also have 0.5-1mm for choice.