Our "Terminator" martial arts mats feature a dense 1-3/8" thick firm polyethylene foam core, covered in durable 18 oz vinyl fabric. Perfect for martial arts, stretching and a variety of high-impact activities, they provide exceptional shock absorption and proper footing. Velcro is sewn into all four sides of the mat, making it possible to join mats together to form large areas. Terminator mats are fabricated in 10' x 10' size, with a single fold to facilitate compact storage. Also offered with a double layer (2-1/2" thick) foam core for extreme impact absorption.