This 9/16" 12 Point Full Polish Ratcheting Combination Wrench by Armstrong produces more torque and while reducing wear and tear providing greater strength and durability. The ratcheting box end has reversing lever that speeds the removal / installation of fasteners and the ratcheting box end incorporates a 72 tooth precision machined gear for a 5° swing arc. By being an enclosed, the ratcheting box end adds strength by reducing dirt and debris infiltration while it's thin walled, low profile allows for easier access to confined fasteners. Incorporating a radius corner design, the ratcheting box end engages the flats of the fastener, not the corners, providing up to 15% - 20% more torque while reducing fastener rounding thus enhancing the turning of worn fasteners. The open end incorporates anti-slip notches that engages the flats of the fasteners, not the corners, providing more torque while reducing fastener rounding. Manufactured from high alloy steel using the most up-to-date manufacturing process and heat treat from greater strength and durability.