The RiversEdge Model 18.300 Rotational Disc is made from 3/4" birch veneer plywood with a heavy-duty ball-bearing swivel plate. The 13" diameter top is completely covered in textured rubber matting for added safety during use.The 18.300 Rotational Disc and Twist Board has many applications including range of motion, strength training and physical rehabilitation. Thank you for buying American-made products.