R-MO STEEL: Provides the strength and flexibility to handle high torque impact tools. RADIUS CORNER DESIGN: Reduces wear and increases torque on fasteners by placing force on fastener walls rather than fastener corners. CHAMFERED OPENING: Quickly aligns fastener to socket. DUAL SIZE MARKINGS: Laser etched and roll stamped markings to ensure permanent socket identification. HEAVY DUTY STORAGE CASE: Convenient impact socket transport and storage. 48 Piece set, 1/4" Drive SAE/Metric, 3/16" - 9/16", 4mm - 15mm, Standard/Deep