The Knotty Tiger® Knot Buster® is a hand-held massage tool that delivers “elbow deep” pressure that can “dig” into some of the tough, tight muscles without the hard work. The design fits perfectly in the palm of a hand to save fingers, thumbs, and hands from fatigue. Three trigger point curves to apply differing amounts of pressure. Non-slip grip feature. Hard, firm, and smooth surface glides over the clothing. 2.75″ massage surface.