Proto 6 Point Impact Sockets are ideal for use on stubborn or damaged fasteners, and also on fasteners made from soft materials. Minimizes fastener rounding, helps to extend fastener life The TorquePlus design allows for quick and easy socket engagement to the fastener flats, not the corners Heat treated for the correct balance of strength and hardness. Allows up to 15% more torque to be applied to the fastener, Made in USA