Big Horn 19126 6 Piece, Drill Stop Set, For Use On Twist Or Brad Point Drills To Prevent Excessive Drill Penetration, Positive Depth Control Assures Exact Hole Depths For Multiple Drilling Jobs, Black Oxide Finish On Cold Rolled Steel, 6 Sizes From 3/16" To 1/2". Sizes included are 3/16, 1/4, 5/16, 3/8, 7/16, and 1/2 inch diameters. Includes Hex Wrench. Use the Big Horn 19126 6 Piece 3/16-Inch to 1/2-Inch Drill Stop Assortment on twist or brad point drills to prevent excessive drill penetration.