BETTER RESULTS – Provides a full range of motion you can’t get from standard sit-ups; isolates the abs for optimal workout results! NATURAL ARCH - Arch design naturally curves to the back for more effective core work that protects your lower back GREAT FOR CROSS-TRAINING – Perfect for high rep exercises like crunches, sit-ups and leg lifts; Ideal for head protection during handstand push-ups DURABLE – High-density foam gives comfort and the perfect amount of firm support for your back and spine while challenging your core muscles DIMENSIONS: 15”L x 12”W x 2.5”H; the compact design is one-size-fits-all and portable so you can carry it to the gym or even while traveling