Mil-spec Passivated Black Oxide Allen (4); ¼”-28 x 7/8” Allen head Hex Key Size: 3/16", high grade zinc plated steel tooth lock washers included Great replacement for slotted / hex screw on rifle platforms Compatible with A2 and aftermarket including B5, BCM, Ergo, Hogue, and Magpul grips All screws, packaging and material made to last! Mil-spec Passivated Black Oxide Allen (4); ¼”-28 x 7/8” Allen head. Compatible with A2 and aftermarket including B5, BCM, Ergo, Hogue, and Magpul grips. All screws, packaging and material made to last! 8 pieces total 4 screws and 4 washers.