Allen 56318 Metal Fold-up Inch Long Hex Key Set, 9-Piece The product is Highly durable This product is easy to use The product is manufactured United States Heat treated, tempered alloy steel provides high strength and resistance to rotational distortion Rotates to 270-Degree to a firm stop for better torqueing and access Nickel-Chrome-Moly alloy steel provides outstanding torque strength All hex keys are precision formed to exact dimensional tolerances for precise fit Proudly Made in the USA by Allen, manufacturers of the original Allen hex key wrench