Ab Matfundamental core training accessory, flexes the spine to lengthen the abdominal muscles for more effective sit ups using compound movements. The Ab Mat is a uniquely designed to provide the full range of motion necessary to train the entire abdominal muscle groups. Specifications: Dimensions: 15" L x 12" W x 2. 5" H One Size Fits All Easy Portability No Set Up Low compression set foam and durable vinyl construction Stable positioning on almost any