Akeda 3447 is 1/2-Inch to 8.0mm Collet Reducer. Akedas new 8mm shank bits replace their previous 1/4-Inch shank bits. Theyre stronger and you will experience less vibration. You may need this 1/2-Inch to 8mm collet reducer in order to use the Akeda dovetail and/or straight bits if your router does not have an 8mm collet.