Swift Sur-Lok Magnum 6-18x44mm PA RiflescopeSur-Lok System Locks the Windage and Elevation - No Shifting Under Recoil.By popular demand, Swift has re-introduced their Sur-Lok reticle system in an improved and simpler design. In the unlocked condition, a Sur-Lok scope adjusts windage and elevation against the usual erector tube spring tension. But once you're sighted in, you turn the Sur-Lok knob to lock the setting. This makes it impossible for the reticle to flex against the springs and change zero when bumped by magnum recoil or rough handling. Swift riflescopes are now Swift Premier SRP riflescopes. We call them Super Resolving Premiers (aka SRP) because the most significant improvements seem to be in the light gathering and clarity of the optics. A proprietary new lens coating is said to be Light Amplifying. They have long eye relief as well... Most are near 3 inches or better. The elevation and windage adjustments feature low profile target knobs with dust covers. Swift Premier SRP riflescopes have fully multicoated lenses with full saddle one piece tube construction and feature Speed Focus eye pieces for best reticle focus. Also available:669M and 669MA. All SRP riflescopes come with a free screw-on sun shade.
Flip Open cover size: Eye 18 and Objective 40Honey-Comb Sunshade: Size 5