Black HoleSuper compact, yet super tacky end pin rest for cello or bass. Works on almost any surface, even marble and parquet floors. The Black Hole Cello Mat is a simple and effective means of holding the cello in place the smoother and harder the floor, the better it works. Just place the Black Hole Cello Mat in position and let Dycem's unique non slip properties do the rest. No messing around with strings round the chair legs!! Easily carried in the pocket