Features and Benefits:

• Forged from the finest chrome-molybdenum alloy steel, the best choice for strength
• Radius corner design extends the life of fasteners; design drives the side of the fastener instead of the corner
• Design also avoids rounding of rusted or damaged fasteners
• Black oxide finish and has etchings for identification

This is an impact socket and it is 13 mm. It is 1/2 in. drive and 12 point. 12-point design means less wear on the fasteners.