The Kolstein Ultra Formulation Supreme Double Bass Rosin - Duo is made by Kolstein & Sons, Ltd. They produce an outstanding rosin using their Ultra Formulation Supreme recipe.
Very minimal powdering and excellent grip equate to quick response and consistent sustain for both the veteran and beginning bassist.
It is a good rosin for players with respiratory difficulties.
The Kolstein Ultra Formulation Duo Rosin contains half moons of the Hard and Soft Bass Rosin in one container.