1/2" Keyless EXTRA 50-RV, Size 13 Drill Chuck, 1/16" - 1/2", 1.5mm - 13mm Capacity With 1/2-20 Threaded Mount Fits Most Dewalt 1/2" Drills. Rohm Part # 1322451
Bestgle 1/2-20UNF Mount 1.5-13mm Capacity Key Drill Chuck for Air Impact Wrench Converter Conversion Tool with Chuck Key and 1/2 inch Socket Square Female Adapter - Amazon.com
Accupro - 1/2 Inch Shank Diameter Straight Shank Micro Drill Chuck Adapter and Chuck - 41868365 - MSC Industrial Supply