Features: [Improve sound effect] the viola rosin have a good viscosity and that great grip and sound penetrating, produces a beautiful, powerful whole sound, can make the music instrument sensitive and timbre. [Set of 2 shapes rosin] comes with 2 different shapes bows rosin, 1 round and 1 square rosin, available to deal with for all types of strings. [Natural rosin] these the cello rosin are made of good quality natural rosin, in a handy container to hold it easier without touching the actual rosin, easy to apply, low dust, high viscosity not brittle and not easy crack. [Wide applications] the rosin is suitable for horsehair or synthetic hair , which is commonly applied for the high pitched violin and viola, and also improve the lower pitched cello's treble tones. [safety and Health ] Rosin with Good quality and low dust rosin protect human body against the harm.