All Excalibur lenses are produced from a Plano Convex glass, optically centered, and have anti-reflective coating. The Excalibur Lenses continue to be a dominate force in target archery. The Super Scope 1 3/4" lens size is 1.75" (approximately 1 3/4") for use with the 040-4 scopes. The lens weighs 155 gr. 6 POWER