ESS Eye Pro Replacement Lens for Crossbow Ballistic Eyeshield, Polarized Gray Experience the Tri-Tech Fit frame that achieves an amazing universal fit with max comfort and zero pressure points. Optimal stability is attained by balancing weight evenly throughout the frame When you're ready to switch lenses, the innovative DedBolt Lens Lock pivots up for easy release, then clamps down for rock solid retention under impact As you stare down your objective through ESSOPTICS, you'll experience distortion-free optical precision throughout the entire field of view ClearZone FlowCoat Technology. These advanced lens coatings are engineered to maximize scratch resistance on the outside and fog resistance on the inside