Hex Key, Tip Size 5/16 in, Long Arm Length 6 in, Short Arm Length 1 1/4 in, Black Oxide/ LONG ARM LENGTH: 6.000 INCHES NOMINAL SHORT ARM LENGTH: 1.250 INCHES NOMINAL WRENCHING SURFACE SIZE: 0.313 INCHES NOMINAL BOTH ENDS WRENCHING SURFACE SHAPE: HEXAGON BOTH ENDS EXTERNAL MATERIAL: STEEL OVERALL SURFACE TREATMENT: OXIDE OVERALL STYLE DESIGNATOR: 120 L-HANDLE