Highly sensitive door stopper: The door stopper features an 80-decibel alarm function. Equipped with a highly sensitive intelligent sensor chip, the device sounds an alarm for up to 5 seconds when vibration is detected. Powered by 2 large-capacity button cell batteries, it offers an extended standby time for lasting peace of mind.Durable and lightweight: This anti-theft integrated door stop is constructed from lightweight aluminum alloy. It offers excellent load-bearing capacity and durability while remaining light and portable. Weighing only 252 grams, it is compact and easily passes through security checks. Includes a dedicated storage bag for convenient transport.Innovative design: This metal lever door stop alarm features a triangular integrated design that utilizes principles of physical mechanics. It effectively directs the force from the door to the floor, shifting the center of gravity to achieve a stable door-holding effect. The non-slip rubber pad on the bottom provides strong support and ensures stability on various surfaces.Easy to install: This door stop is simple to install and remove in just three seconds. No drilling or tools required. Simply place the door alarm in the gap between the door and floor, then tighten the screws clockwise. (Note: the gap between the door and floor must be between 5 and 25 mm.)Security protection: This retractable alarm door stopper helps deter unauthorized entry, making it ideal for use in hotels, during travel, for solo living, or business trips. Provides added awareness of door movement, offering enhanced personal security and peace of mind while indoors.