Allen 56628G 8-Key Metric Hex Key Fold-Up Set From Allen, the original manufacturer of the hex key Heat treated, tempered alloy steel provides high strength and resistance to rotational distortion All hex keys are precision formed to exact dimensional tolerances for precise fit Rotates to 270-Degree to a firm stop for better torqueing and access Dual material case is color coded for quick identification: SAE - green, Metric blue