These are the inserts sold to go in AppleCheeks Envelope pocket nappies. They are rectangles (32 x 42cm) of soft slightly stretchy fabric (70% bamboo + 30% organic cotton), which can be folded in different ways according to your needs. They come in 2 versions - either two or three layers of fabric. The three-layered version is thicker and will give better absorbency than the two-layered sort but will be slower to dry. They can be used as inserts in a pocket nappy or as an extra booster in any nappy.
If you fold the rectangle in four along the short axis, it makes a 8 or 12 layer pad of much the same size as a LittleLamb or Baba+Boo pocket nappy insert. Folded in three, it makes a wider booster which would work well in a night-time nappy. If you fold it lengthways you can make a longer, narrower pad.
These boosters combine the absorbency of a really thick booster with the dryability of a flat nappy. What's not to like?