From the Manufacturer

The Empire 6-Inch heavy duty professional combination square with etched stainless steel blade is a great tool for any carpenter. The steel blade has metric graduations, machined square head, self-aligning draw bolt and hardened scriber. It also offers a true blue vial for accuracy. Empire Level is the home of True Blue – the most accurate vials in the world. The newly designed True Blue Series of levels and squares are engineered to provide maximum accuracy, extreme durability, and enhanced readability with the strongest warranty in the industry. Empire Level is the leading designer and innovator of accurate levels and measuring tools. The blue fluid in our level vials is Empire’s unique symbol of superior accuracy and a trademark of Empire Level Mfg. Corp.
Precision machined square head and True Blue vials ensure sureness to .001
6-inch etched stainless steel blade with metric graduations
Self aligning draw bolt and hardened scriber
True Blue vial is guaranteed accurate to within .00050 inch for maximum accuracy, extreme durability and enhanced readability
Made in USA