Matte Black Anodized CNC Machined 6061-T6 Aluminum and Steel Construction. Staked and Knurled Thumb Wheels Can Be Tightened by Hand in the Field or by a Flathead Screw Driver or M6 Hex Wrench (Recommended Torque Value: 25 in-lbs). A2 Dual Aperture and 6/3 Windage Drum. MIL-STD-1913 Picatinny Compatible Squared Recoil Lugs for A Secure Zero Hold and Return to Zero. Compatible with In-line Rail Mounted Front Sights and Taller F-marked Front Sight Bases