Rockler Router Collet Extension for 1/2'' Shank Bits | Rockler Woodworking and Hardware
Yakamoz 1/4 Inch Shank Router Collet Extension Milling Cutter Bit Rod Chuck Extender Adapter Extends an Additional 2-1/4" for 1/4" Router Bits Only - - Amazon.com
Router Collet Extension-Rod Router Bit Adapter Extender For 1/4\ 8mm 12mm Shank | eBay