Die Grinder Router 1/4 to 1/8-inch Adapter Chuck Collet - - Amazon.com
1/2 1/4 Inch 8mm Shank Router Bit Collet Extension Rod Chuck Converter Adapter | eBay
Makita USA - Product Details -763803-0
Reducing Collet Adapter 1/4" to 1/8" - OpenBuilds Part Store
1/4'' to 1/8'' Collet Reducer | Rockler Woodworking and Hardware
Amazon.com: 1/4 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) :