ProBasics Transfer Bench 300lb Weight Capacity Cushions Gel Available in Natural and Dark 1521 Available in Natural and Dark Cherry finish Accepted by leading authorities as a simple and accurate method for discovering congenital color blindness and red green blindness each in two forms complete and incomplete * Includes four special plates for tests to determine the kind and degree of defect in color vision * Makes use of the peculiarity that in red green blindness blue and yellow appear remarkably bright compared with red and green * Color plates encased in specially designed album type books for ease of handling * Detailed instructions included Legs have one inch easy snap button adjustments Durable blow molded bench and back have a textured surface and are contoured with drainage holes to reduce slipping