Nightforce Ultralite Rings 30mm 1.0 Med 4 Screw Xtreme Duty A101 are lightweight and remarkably strong due to 7075-T6 hard anodized aluminum bodies and titanium beta crossbolts and jaws. Available in both four-screw and six-screw versions. Crafted of machined 7075-T6 hard anodized aluminum, with titanium crossbolts and jaws, they give you the performance of steel at half the weight. This unique construction provides strength well beyond that normally found in lightweight rings. Available Nightforce X-Treme Duty 30mm 4 Screw Ultralite RingsMPNCenterline HeightHeightA118.885"LowA1011.0"MediumA1071.125"HighA1081.265"IntermediateA1101.375"X-HighA2031.5"XX-High Nightforce 1.00 Medium UltraLite 30mm Ring Set A101