SK Hand Tools 401 1/2-Inch Female and 3/8-Inch Male Adapter 1/2-inch-to-3/8-inch adapter gives greater flexibility for all sockets and drive tools Patented SuperKrome finish for durability and maximum corrosion resistance Spring loaded steel ball for ease of use Ball detent securely holds socket to coupler Measures 0.87 inches in diameter; 1.36 inches in length