5 piece. DoubleLok Technology ensures both ends of bit lock securely in impact drivers and quick-change chucks, enabling use of two tips from one bit for added convenience and extended life. Precision tip geometry delivers superior fitment, reducing stripping and cam-out. Power Groove designed for compatibility with IRWIN Impact Performance Series Magnetic Screw-Hold Attachment. Manufactured with heavy-duty, cold-forged, high-grade steel to withstand high torque output. Includes: #2PH/#2PH (2), #1PH/#2PH, #2PH/#3PH and attachment. Square head.