Fitment: Works with a massive range of tools. Fits most 6mm to 19mm metric and 1/4″ to 3/4″ SAE combination wrenches, as well as 6mm to 12mm and 1/4″ to 3/8″ hex keys (Allen wrenches). One adapter replaces the need for multiple specialized tools Features: 1) Built to last with heat-treated alloy steel and a corrosion-resistant black oxide finish. The 3/8″ square drive is rated for a maximum torque of 100 lb-ft, ensuring dependable performance on demanding jobs. A must-have quality tool to your professional or DIY toolbox .