The Elite Medical Instruments Deluxe Eye Occluder and Snellen wall chart set. The Deluxe Eye Occluder features an occluder that is shaped to cover either eye during an eye examination. The occluder is constructed of black plastic. The Snellen Eye chart is used to perform a visual acuity exam. The patient should be about 20 feet in front of the eye chart to perform an examination. The eye chart is made out of Plastic, washable, and non reflective. The chart is 22 inches by 11 inches. Perfect for a 20 feet eye exam. The charge also features a ring on the top to assist when mounting on a wall. Perfect for students, optometrists, offices, and schools.