Masterpiece Arms BA Rings are designed primarily for the discerning hunter who wants to use the best rings available to ensure optic consistency and assurance the rifle is on plane when taking that most important shot. The rings are sold as a set. On one cap, there is a built in leveling system. The profile and location are specifically designed to allow the hunter to see the level with the shooters weak eye, while the strong eye is on the target through the ocular lens on the optic. All this is completed while the shooter is down on the rifle. No need to take your eyes off the target to ensure the rifle is not canted. The low profile, snag free location is designed so that the leveling system does not catch on limbs or heavy brush when the rifle is carried by the hunter. The width of the rings, 1a ^2, provides an extreme clamping surface area as compared to similar products. The BA Rings have a grip on the optic tube that simply will not allow movement. Don't let skinny little, light duty rings get in the way of harvesting that trophy you have worked so hard to achieve. Like all products from Masterpiece Arms, these MPA BA Rings are designed for a purpose. To give the hunter, his rifle and optic, the highest level of assurance for a successful shot.