Premium Material: This architect key is made of high quality steel, the material is safe and hard, the surface is coated with bright nickel, it has good corrosion resistance and is durable.< /p> Design Concept: This universal structure wrench has a 3mm hex key and a short gear on the tip, a flat cam and 3 square keys on the top. At the same time, it has a measuring scale, which is very convenient. Product parameters: 3 square keys in sizes 6, 7 and 8 mm. For checking heating valves or opening ventilation grilles, a practical scale on the side allows cylinder lengths of 25 to 75 mm to be measured. Versatile: the construction key is a ruler for measuring the angle of a profile cylinder. Also ideal as an aid for checking cabinet keys or loose door handles, and also as a bottle opener.