Amazon.com: 1/2 Inch Shank Router Bit Collet Extension Chuck Converter Adapter, Convert 1/2-Inch & 1/4-Inch Shank Bits with ER20 Spring Collet, ER20 M Type Collet Chuck Wrench Spanner -(Pack of 4) :
Rocky 30 Trim Router
Rockler Router Collet Extension for 1/4'' Shank Bits | Rockler Woodworking and Hardware