5th Season Abdominal AB Mat 15" x 12" High Density Core Trainer with Trigger Point Muscle Massage High density, durable foam gives comfort and the perfect amount of firm support for your back and spine while providing a challenge to your core muscles 15" x 12" x 2.5"; the compact design is one-size-fits-all and portable so you can carry it to the gym or even while traveling trigger point works great for those with lower back pain problems who want a safe way to continue strengthening their abdominal muscles. Arch design naturally curves to the back, allowing for more effective core work while protecting your lower back and tailbone Perfect for home, office, gym, yoga, crossfit, boxing, MMA, and other types of training - For developing a strong abdominal core