Manufactured as per ASTM D 4280. Road Stud / Cat Eye / Reflective Pavement Markers are durable, impact and weather resistant. Diamond grade micro prismatic optics provide excellent wet and dry reflectance. Normal Reflective Area of Each Lens 16.8 sq. cm. The tough retro-reflective lens is coated with a superior protective material that combines ceramic and polymeric elements, adding more resistance to abrasion. size - 100