Mark 4 Tactical series of scopes are ideally suited to the special needs of the military and high intensity law enforcement organizations. Scopes feature parallax adjustable from 50 yards to infinity using turret mounted focus knob, superior edge-to-edge sharpness across visual field and outstanding low-light capability, audible and tacticle windage and elevation adjustments, 30mm maintubes offer extended windage and elevation adjustment travel and the tube is milled from a single piece of 6061-T6 aircraft aluminum. These American made scopes are covered under Leupolds Full Lifetime Guarantee.