Leupold Mark 4 Rings come in a variety of heights and sizes built from heavy-duty materials to ensure maximum durability in all types of weather. These rings are constructed from either 7075 T651 aluminum alloy or 11L17 cold-rolled steel depending on the model. If you are looking for a set of mounting rings that are built to last look no further than Leupold Mark 4 Rings. These rings were designed with a large contact area to reduce scope movement while large hex nuts enable you to achieve fast torqueing and quick adjustment.