Designed primarily for AR-15 and AR-10 rifles, these are also compatible on various MSR platforms. A four screw ring cap design paired with a 2-nut base and recoil lug cross-bolts. A scalloped profile increases surface area while reducing mass, ensuring these rings will hold your scope tight! Athlon's value priced Armor Cantilever Mounts feature a snag free, lower profile design. Ideal for hunters and plinkers alike!