3-Pack Keyless Chuck, 1/32" to 1/8" Replacement 4486 Drill Keyless Bit Chuck Shank Rotary Tool Quick Change Adapter Kit Compatible for Dremel 4486 Model 395 3000 4000 4300 8220 3000 7300 Multipro - - Amazon.com
Dremel Chuck Adapter in the Rotary Tool Attachments & Batteries department at Lowes.com
4 Types Multi Chuck Keyless For Dremel Rotary Tools 0.3-3.2mm Drill Bit Chucks Adapter Converter Universal Mini Chuck Dt6 - Power Tool Accessories - AliExpress