Big Horn 19123 Split Ring Stop Collar 7Piece Set

From the Manufacturer

Big Horn's 7 piece split ring stop collar set is designed to grip the entire diameter of your drill bit without screw ever touching the shaft. Used to accurately control the depth of the hole you are drilling. These split collars hold securely in place where you put them every time. Sizes fit bits 1/8-Inch, 3/16-Inch, 1/4-Inch, 5/16-Inch, 3/8-Inch, 7/16-Inch, and 1/2-Inch. 7-piece set comes with allen wrench.