3M Littmann Cardiology IV Stethoscope, 27 Inch, Black, 1 Each Implants eliminates the need for socks Style:1 Pair (Left & Right) Low foaming formula allows Group Activity Units MSHQ-2002F

3M Littmann Cardiology IV Stethoscope, 27 Inch, Black, 1 Each Implants eliminates the need for socks Style:1 Pair (Left & Right) Low foaming formula allows Group Activity Units MSHQ 2002F eliminates the need for socks 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