First Focal Plane Reticle: Scale of reticle remains in proportion to the zoomed image. Constant subtensions allow accurate holdover and ranging at all magnifications; 34mm tube: Provides a large amount of travel; RevStop Zero System: Patented streamlined design offers a toolless zero stop for rock-solid return to zero after turret adjustments; Throw Lever: The included throw lever can be installed for quick and easy magnification adjustments