General Tool Drill Grinding Attachment, The Original 825

https://www.penntoolco.com/general-drill-grinding-attachment-the-original-825/

General Drill Grinding Attachment, "The Original"

Equally at home in machine shop and home workshop.
Engineered to permit sharpening of drill bits to factory accuracy.
Extends the life of drill bits.
Angle adjustments lock in to grind drill bits for more accurate drilling in a variety of materials.
Automatically adjusts to give correct clearance angle.
For use with ANSI, OSHA, and UL approved standard electric bench grinders or surface grinders.
Instructions included.
For fractional drills 1/8 to 3/4"
for number size drills 30 to 1
for letter size drills A to Z
for millimeter size drills 3.0 to 19.0mm