You've never felt relief like the Chirp Wheel XR. The Extreme Relief 3-Wheel Pack offers three unique ways to relieve pain through a combination of massage, trigger point therapy, and stretching. TYPES & DESIGN: 10" Acupressure Wheel designed to massage pressure points around your spine while also providing a 4-way stretch It also includes a 6" Knot Kneader Wheel that mimics a kneading motion on the soft muscle tissue surrounding your spinal while offering an intense stretch The 4" "Tech Neck" Relief Wheel is designed to apply gentle pressure to the suboccipital trigger points in your neck, loosening your neck and upper back muscles that are strained due to excessive neck strain from cell phone and monitor screens Each wheel can support up to 500 lbs. WARRANTY: 10 Year Warranty against manufacturer's defects