Unique design flexes up to 45° to grip the direct fuel line from any angle; Provides ability to tighten and loosen nuts on direct fuel line without losing torque; Especially useful for BMW N54 / N55 & N63 engines where steel lines cross over valve cover; 3/8" Square Drive; Includes sizes: Open Stock; #1821 - 11mm; #1823 - 13mm; #1824 - 14mm; #1825 - 15mm; #1827 - 17mm