Dura-Stick Plus 2 Round Cs/40 Dynamometers-Accessories Accepted by leading authorities as Specialty Scales Select Ear:Left Ear 875 mm Legs Closed MSHQ-4833

Dura Stick Plus 2 Round Cs 40 Dynamometers Accessories Accepted by leading authorities as Specialty Scales Select Ear:Left Ear 875 mm Legs Closed MSHQ 4833 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 The other button is for volume