The Tangent Theta 3-15x50 has been created to provide shooters with a scope that functions under extreme duress without compromising its inherent accuracy. Featureing a Tool-less re-zero Gen 2 XR reticle and precise tactile turrets this Tangent Theta is the perfect option for any long range tactical application.To use a riflescope with your firearm you'll need a mounting base and mounting rings in addition to the scope itself. Bases attach to your firearm and the rings attach your scope to the base. Proper spacing of the rings as well as the ring height should be considered to ensure a proper line of sight can be established. This will maximize the value of your investment and enhance your shooting experience. It should be noted that in many mounting applications a professional gunsmith's skills will be needed for proper installation.