Lens holder and anti-roll device Includes red, blue, and clear lenses The red lens is used to help maintain night vision. General applications include: aircraft, boats, ships, military operations, police and security work. The blue lens helps penetrate through smoke and fog. The clear lens is a replacement for the existing lens.table.productattributes, .productattributes td { border-bottom: 1px solid #ddd; border-collapse: collapse; padding: 2px; text-align: left; }