4 layers insert, the outside 2 layers are 250g bamboo, the inside 2 layers are microfibre. This makes it super absorbent.

5 layers design, the outside 2 layers are 100% bamboo charcoal, the inside 3 layers are microfiber. This makes it super absorbent

These inserts are made of super absorbent microfibre, more absorbent than regular flannel and dries much faster.