Leupold FX-II Ultralight 2.5x20mm Wide Duplex Leupold's classic/standard fast focus eyepiece with a low profile lock ring makes reticle focus easy to achieve and maintain 1/4-MOA field-click adjustments for windage and elevation Durable and compact, the one-inch maintube is lightweight and fits more legacy rings Made with Leupold's Proprietary nitrogen sealing process, which has become the industry standard DiamondCoat lens coatings on exterior lens surfaces provides the ultimate in abrasion resistance