Crimson Trace CTL-3420 3 Series Tactical Riflescope 4-20x50mm is a feature rich 4-20x50mm mid-range rifle scope that has been purposefully built from the ground up. The scopes First Focal Plane (FFP) and impressive Japanese ED glass clarity makes for an unparalleled shooting experience. The custom designed LR1-MIL advanced reticle is fully illuminated and offers quick hold-over points for windage and elevation. The exposed .1 MIL tactical turrets provide a precise and rugged feel when dialing for the most accurate of shots. The entire Crimson Trace Scope Line offers EZ Mount Leveling Indicators for quick and exact mounting and red alignment ring for proper eye placement. The 4-20x50mm scope makes objects seem four to twenty times closer than with the naked eye, featuring a 50mm Objective Lens. The glass etched, LR1-MIL Advanced Illuminated reticle sits in front of the magnification mechanism, scaling to provide correct ballistic hold points at any range. This feature allows the reticle to be sighted in at any part of the magnification scale and precise range measurments. Numerous windage holding points allow for on the fly adjustments during ever-changing environmental conditions. A Single piece 30mm Anodized Aluminum main tube is constructed to handle the most demanding environments. It is waterproof and fog proof with coated lenses to protect from scratches, oil, and debris and is nitrogen purged and O-Ring sealed.