DESIGN & BENEFITS: The 10" Chirp Wheel XL has all of the same features of the best-selling Chirp Wheel Plus, but also has a 40% wider base that provides extra stability The EVA foam is 50% thicker providing a comfortable surface, perfect for sensitive backs or people looking for a little less pressure Chirp's Patent pending Spinal Canal(TM) removes pressure off of your spine allowing you to get a deep 4-way stretch that will elongate your spine by relieving pressure between the joints The 7 inch width of the Super Comfort Wheel fits right between your shoulder blades, applying pressure right where you need it most Improves posture and mobility SPECS & WARRANTY: Supports up to 500 lbs. 10 Year Warranty