Feature: - The lens serves as a critical piece of protection for your NVG lenses, shielding them from dust, dirt or scratching that may cause expensive repairs and potential downtime. Provides the ability to see objects at all distances without adjusting the focus on Night Vision Goggles. - Clear front sacrificial lens to protect lens of NVGs and prevent dust and debris from entering apparatus. - Rapid adaptation to ambient light by turning the adjustment ring, opening or closing the iris.more focusing - Easy and secure attachment to end of NVGs.