Leupold Quick Release Two Piece Bases. Leupold QR mounts allow you to remove and reattach your scope and return to within 1/2″ of the original point-of-impact. The patented lever mechanism, machined with precision tolerances, engages the steel base to the ring, pulling it down and forward and locking it into its “zero” position. You get ease, convenience, and field-proven, repeatable accuracy