The AB No 2 Cello Rosin is a very popular rosin for cello. It is supplied in a green cloth wrap and is made in the UK.
Rosin is a natural product made from the resin secreted by fir and pine trees. The resin is heated and mixed with oil and other ingredients, then cooled and allowed to solidify in the now familiar cake form.
The carefully guarded recipes vary considerably and are carefully formulated to suit different types of strings and playing styles.