Highly sensitive door stopper: The door stopper has a shrill alarm function of 80 decibels. Equipped with a highly sensitive intelligent sensor chip, the host immediately sounds an alarm for up to 5 seconds when it detects vibration. Built-in 2 large-capacity button cells, ultra-long standby time, enjoy a lasting sense of security. Durable and Lightweight: This anti-theft integrated door stop is made of lightweight aluminium alloy. Not only does it have excellent load-bearing capacity and durability, but it is also light and easy to carry. Weighing only 252g, it takes up no space and can easily pass various security checks. It also comes with an exclusive storage bag so you can take the seat belt with you. Design innovation: This metal lever door stop alarm has a triangular integrated design and cleverly applies the principles of physical mechanics. It cleverly directs the force with which the door is pressed to the floor, changes the centre of gravity of the force and effectively achieves a stable door holding effect. The non-slip rubber plate on the underside provides strong support and can remain stable on a variety of surfaces. Easy to install: This door stop is quick and easy to install and takes only three seconds to install and remove. No drilling or tools are required. Simply place the door alarm in the gap between the door and the floor and tighten the screws clockwise. (Note: the gap between the door and the floor must be between 5 and 25 mm). Security Guard: With this retractable alarm door stopper, you don't have to worry about uninvited guests entering, whether you are staying in a hotel, travelling, living alone or on a business trip. If you live alone, you no longer have to worry about any unusual movements outside your door. It's like having a private bodyguard on hand, allowing you to sleep peacefully until dawn.