10 health benefits of bulletproof coffee D28 Readers Bullet Coffee D28 Readers D28 Reading Glasses Bullet Coffee Brown Caddis Caddis D28 Compact Prescription Glasses Caddis. For those fans of substance, this frame will not fold four different ways into a square the size of a Starburst. D28 is a hearty helping of precision cut, 100% acetate with Izquierda and Derecha laser etched across the top in case you forget which side is left and which is right. A premium hard coating protects lenses, increasing durability and minimizing scratches. Lenses include a high performance water, dirt, and grease repellent coating for easy maintenance and superior optics. Premium, bio based acetate frame with 5 barrel industrial hinges.