Sunex 2501 1/2-Inch Drive Locking Impact Extension Set, 3-Piece Useful in hard to reach areas where a positive lock on the socket is required Feature a positive locking ball detent and sliding collar for quick release of sockets and accessories Includes 3", 6", and 12" locking extensions Radius corner design of square drives reduces socket wear over time Forged from high quality cr-mo alloy steel