High quality, industrial grade, professional set. Made with Eklind alloy steel. Heat treated for optimum strength and ductility. Finished with Eklind Black finish to resist rust. Includes plastic holder which firmly retains each key in a size marked hole Sizes include: 1.5mm, 2.0mm, 2.5mm, 3.0mm, 4.0mm, 5.0mm, 6.0mm, 8.0mm and 10.0mm. Color coded blue for metric. Made in the U.S.A.