Magic Rosin® is a premium quality, professional-grade rosin that provides excellent grip and delivers a clear, complex tone. It is used by string players of all ages and ability, from soloists to students. Magic Rosin is available in two formulas; 3G or Ultra. 3G is a grippy rosin designed for violin and viola. Ultra is grippier than 3G and it is recommend for cellists, bassists, or any advanced string player seeking more grip and "pop".