Durable material: the universal building key is made of high-quality zinc alloy, with a nickel-plated surface, which has rust and corrosion resistance, is not easy to deform, is robust and durable, and can be reused for a long time. Practical design: the universal building key has a cylindrical lock nose for PZ core locks, and there are no irregular cylinders in the shell structure. And with a practical scale design, it is perfect for shell structures. Easy to use: on the cylinder of the universal building key there is a laser-engraved scale with a length of 22-75 mm, accurate scale, clear writing and a pointed end with a 3 mm socket wrench. It is easy to use and is very suitable for checking heating valves or opening ventilation grilles. Multifunctional use: universal building keys are widely used, with a pointed hexagonal socket wrench, which is used to loosen or secure the door handle. The graduated metal building key can be used perfectly for the shell structure. The universal building key is an ideal aid as a control cabinet key or if door handles are not yet installed. The package includes: you will receive a universal building key with pointed hex and a universal building key short with 3-square key for checking heating valves or opening ventilation grilles. The universal building key is easy to carry and not easy to tear and can be accurately measured for long-term use. Very suitable for measuring cylinder dimensions.