Ishihara 38 Plate Chart Book for Color Blindness Defibrillation Roll In Buddy With Tilt * Autoclavable Up to 325 Roll In Buddy With Tilt * The Roll In Buddy is an ergonomic shower commode chair used in roll in showers or for toileting * The Roll In Buddy features all the corrosion mold resistant components standard to all showerbuddy products * Weight Capacity: 440 Lbs 30 mm Front Twin Casters 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