ESS Crossbow Replacement LensPhotochromic. These sunglasses produced by the experts at ESS are interchangeable allowing shooters to easily adapt the lenses to changing light conditions. The ESS Crossbow High-Vis Lenses let shooters keep their penetrating sights on target rather than fumbling with a cloudy pair of lenses and the magenta lenses provide excellent contrast. Keep your ESS Crossbow Replacement Lenses flipped open on a sunny day to allow your eyes to adjust to any bright conditions. Specifications for ESS Cross Bow Series Lenses: Compatible with: Crossbow Tri-Tech Fit and Crossbow Suppressor frames Thickness: 2.4mm Material: High-impact Polycarbonate Features of ESS Crossbow Series Replacement Lenses: ClearZone FlowCoat Lens Coatings Extra-Wide Field of View Interchangeable Lenses ANSI Z87.1 Compliant U.S. Mil Spec Package Contents: ESS Crossbow Replacement Lens ESS 740-0452: Crossbow Replacement LensPhotochromic