All Specialty Archery Excalibur Lenses are made from high quality optical glass. The lens has an anti-reflective coating to reduce glare and scratching, and the glass is tempered. This results in a lens that has an extremely clear image with 99.5% light transmission. The lens is optically centered, which is a very important factor to consider when choosing a lens. The Super Scope 1 3/4" lens size is 1.75". For use with the 040-4 scopes. The lens weighs 155gr.