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 SAE sizes .050", 1/16", 5/64", 3/32", 7/64", 1/8", 9/64", 5/32", 3/16", 7/32" and 1/4"; metric sizes: 1.5mm, 2mm, 2.5mm, 3mm, 4mm, 5mm and 6mm. Color coded red for inch and blue for metric. Plastic holders firmly retain each key in a size marked hole. Made in the U.S.A.