5/16 inch 6 point standard 1/4 inch drive socket is easy to read making it the ideal choice. While having dual markings, a laser-etched size marking as well as the standard stamp markings, this Craftsman socket is easy to locate so you have the right tool for the right job. Great for working in low-lit or greasy environments. Permanent marking resists chipping, fading and corroding. Headlock grip gives more contact on the flats of the fastener for more turning force.