FuzziBunz® Micro-Terry Inserts are made of 4 layers of super soft micro-fiber terry cloth. Fiber content of this material is a poly/rayon blend. Micro-inserts do away with any bulk that may have been associated with cloth diapers. Micro-inserts make FuzziBunz® (or any other pocket diaper) super absorbent and super trim at the same time. One insert is all one will need for a daytime diaper. At nighttime, we do recommend using two inserts for maximum absorbency.