Maddak Walker Bag, For Use With Walkers, Cotton, 1 Each 15 20 Pantyhose Accepted by leading authorities as 416700 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 * A high quality porous 100% cotton tape at an affordable price Blue print quilted walker bag neatly hangs over walker crossbar so you can carry things with you that you might not otherwise be able to take along Machine washable