Astro 1144 ONYX 1/2-Inch Heavy Duty Ratchet Wrench High performance motor deliver 60% higher output torque than standard ratchet Precision machined anvil ensure that ratchet pawl & yoke can properly engage with each other at any position "Power forged" P/M planetary gears with nitrading ring gear submit smooth operation coupled with exceptional durability Built-in twin expansion chamber divided by air flow guide fins to reduce exhaust noise Short & robust crankshaft transmits power with low vibration & high efficiency