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. Design Concept: This universal structure wrench has a 3mm hex key and 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 controlling cabinet keys or unassembled door handles, and also as a bottle opener.