Thomastik-Infeld Peter Infeld Violin Rosin is a premium rosin created from pure and high-quality pine resin. Formulated for Thomastik's popular Peter Infeld line of violin strings to provide optimum grip and low dust residue. This violin rosin will greatly enhance the tonal qualities of your strings, especially Peter Infeld Red and Blue, Dominant and Spirit strings. Peter Infeld Violin Rosin is good for warm climates and during summertime. It has a strong grip and softens the whistle of the e-strings considerably. It comes in an attractive soft case.