General Tools & Instruments S838 6 Piece 3/16-Inch to 1/2-Inch Drill Stop Assortment
Use the General Tools S838 6 Piece 3/16-Inch to 1/2-Inch Drill Stop Assortment on twist or brad point drills to prevent excessive drill penetration.  Black oxide finish on cold rolled steel.  Includes hex wrench.  Sizes included are 3/16, 1/4, 5/16,  3/8, 7/16, and 1/2 inch diameters.