This is a new HEAVY DUTY chuck primarily used with Magnetic Drills for easy change to Standard Twist Drilling. HEAVY DUTY 5/8" (16mm) Magnetic Drill Chuck with 3/4" Weldon Shank Adapter. This chuck press fits into the included "JT" jacobs taper adapter, opposite end of the adapter has a 3/4" Weldon Shank.
eBay