These are 8 different color rubber balls which can be simply attached to bottom of tuning fork handle without any adhesive. Each ball has hole in the center and easily fixes on tuning fork handle. For best grip,push the ball at the bottom of the handle at maximum possible level. These balls are removable. These are in 8 different Chakra colors. So, besides giving a better grip, they also help by adding the benefits of COLOR THERAPY to Sound Therapy. These 8 colors are the 7 Rainbow colors plus Purple: Violet Indigo Blue Green Yellow Orange Red Purple