3 sensitivity levels - Low - Medium - High, with a sensitivity adjustment switch on the side. Also functions as a wedge to prevent the door from opening when the power is off. No installation required. Requires one 9V battery. Easy to carry and provides peace of mind when traveling or living alone. Super loud alarm. A 120-decibel alarm sounds when pressure is applied to the door stop. 1. Compact size: Only 42X135X40mm, easy to carry and doesn't take up much space. 2. Lightweight and easy to carry: Weighs only 95 grams, so you can easily carry it in your bag or pocket. 3. Anti-slip bottom design: Increases friction between the door stop alarm and the ground, making it more stable. 4. 120dB super loud alarm sound: The loud sound attracts attention when needed. 5. 3-level sensitivity settings: 3 sensitivity modes: Low, Medium, and High. 6. Dual function: Can be used not only as a security alarm but also as a door lock. 7. Easy operation: Simply insert the battery, turn on the switch, and place it under the door to complete the installation. 8. DIY installation: No complicated tools or specialized knowledge are required. 9. Wide range of applications: Suitable for homes, apartments, dorms, hotels, travel, and other places, providing security.