Kaplan Premium Dark Rosin is suitable for violin, viola, and cello bows and the special Kaplan recipe produces less dust, keeping hands and instruments cleaner. This premium Kaplan mixture and process produces extremely find-grained rosin. The rosin comes attached to the inside of the applicator case, which "locks" shut for clean, easy storage in an instrument case or bag. Once the tabs are squeezed to open the case, the rosin is then applied right from the case, where it can be rotated for uniform wear and maximum use.