High quality, industrial grade, professional sets. Made with Eklind Alloy Steel. Heat treated for optimum strength and ductility. Finished with Eklind Black Finish to resist rust. Eklind ball-hex keys will drive a fastener at up to a 30 degree angle Includes two sets: EKL13213 (long key sizes .050", 1/16", 5/64", 3/32", 7/64", 1/8", 9/64", 5/32", 3/16", 7/32", 1/4", 5/16" and 3/8") and EKL13609 (long key sizes 1.5mm, 2mm, 2.5mm, 3mm, 4mm, 5mm, 6mm, 8mm and 10mm). Color coded red for inch and blue for metric. Plastic holders firmly retain each key in a sized marked hole. Made in the U.S.A.