Corrosion Resistant, High Hardness: Our universal construction key is made of high quality metal. The universal keys are extremely durable thanks to their shiny nickel coating. It is resistant to corrosion and most acids and other corrosive agents. And heat treated and hardened. Make it last longer. Clear Scale and Easy Measurement: There is a convenient scale behind the square key to measure the cylinder length from 25 to 75 mm. Laser engraving. The scale is accurate, the writing is clear and it is not easy to wear. Effectively prevent corrosion and provide accurate measurements for your long-term use. SQUARE CHUCK KEY: Architect key with cylindrical nose for PZ mortise locks, no special shaped cylinder in the housing structure. 3 square keys in sizes 6, 7 and 8 mm. Check the heating valve or open the ventilation grille. Allen key: This universal construction site key has a 3 mm Allen key at the end and a short gear with a flat cam. Used to loosen or secure door handles. The control cabinet and service flaps can also be easily opened. Multifunctional construction key: The construction key is a measuring ruler for measuring the angle of a profile cylinder. The key to new construction lies in the recovery tools, especially in hull construction. The construction key is an ideal helper as a switch cabinet key or as a door handle that is not yet installed. It can also be used as a bottle opener. Size: 19.5*6.8cm Note: The data are all measured manually, please allow 1-3cm error due to differences in light and display, there may be some color differences, please refer to the actual item received.