Drill Master 7 Piece Drill Stop Set to Fit 1/7 3/16 1/4 5/16 3/8 7/16 1/2 Inch Bits Drill holes to the exact depth you need with this 7 piece drill stop set from Drill Master; Comes with Free How to Live Stress Free Ebook Set fits 1/8 inch, 3/16 inch,  inch, 5/16 inch, 3/8 inch, 7/16 inch, and  inch bits Fastening screws included Locks onto the bit for a secure fit and easy use Quickly and reliably drill holes to the exact depths you need