Massage your muscles, and stretch your tight hamstrings. All this is done in with the this ball. the most choice for fitness and rehab professionals. The ball helps your body in a number of ways, including improving your alignment and hip mobility, increasing your core flexibility, and assisting with release. This ball contributes by letting you gently challenge your back, hamstrings, hips, abs, and other body parts to improve your core strength and flexibility. Features - Color: Red and Green. - Material: Silicone. - Diameter: 6.3cm/ 2.5 inches. - Great for trigger point therapy - giving relief from tight muscle knots - more durable and comfortable will withstand heavy use and retain shape - For Pilates, Yoga, Massage Therapy, and Physical Therapy, used by professionals and for home use - Used for stability exercises and release and alignment. - Can use it when watching TV, sitting at your desk, or even while lying on your living room floor. Package list: 4 x Massage Ball Solid Silicone Massaging Mobility Ball Trigger Point Therapy for Exercising (Red + Green)