Premium Wooden Hell Cap (M-1) Discover the benefits of our high-quality dark winter rosin, specially designed for string instrument musicians. This softer rosin variant excels in colder winter conditions with increased moisture. It is essential for violin, viola, cello, and double bass players as it provides the necessary friction for optimal sound production. To ensure optimum sound quality, it is important to apply rosin along the entire length of the bow. This treatment facilitates the necessary friction between the strings, allowing the instrument to produce a richer and more resonant sound. >>> Unfinished 12-14 mm thick or finished caps with desired thickness, complete with machined edges. <<<