Advantages

• Makes drilling of small holes easy by giving operator fingertip feed control independent of coarser quill feed.
• Eliminates the need for special machines to drill small holes.
• Reduces breakage and deflection of small drills.
• Simple to use:
  • Grasp free-turning knurled ring and feed with gentle finger pressure.
  • Spring-loaded. When ring is released, chuck retracts automatically.