108db Loud Alarm: This door sensor alarming is loud enough to detect entry. Suitable for window, door, freezer, file cabinet, etc. 4 Modes: Designed with normal alarm, continuous alarm for 30s, door closing reminder, and doorbell mode to meet various needs. Easy Installation: Install the alarm and sensor to door or window with double sided tape, the distance between the sensor and alarm should be less than 1cm, designed for indoor use only. Power Supply: Powered by 2 pieces of AAA alkaline batteries(not included). remind with LED indicator. Wide Application: Perfect for home, office, cabinet, dorm room, apartment, or shop. Specification: Material: ABS Working Voltage: 3V Alarm Current: 3mA Detection Angle: Horizontal Quiescent Current: 0.1uA Working Temperature: 0 Centigrade Degrees to 60 Centigrade Degrees Detection Distance: 20cm to 30cm Volume: 108db Upgraded Door Closing Reminder Function: The delay time is upgraded to 3/15/30/60s, the default delay time is 15s. Upgraded slower DIDI DIDI prompt sound, not noisy and harsh. There will be a beep prompt after canceling then silent, and prompt after delay. Size Chart: 8.5cmx4.3cmx1cm/3.35inchx1.69inchx0.39inch Package Includes: 1 Piece Manual 1 Piece Door Sensor Alarm Note: 1. Please allow slight errors due to manual measurement. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. 3. Wish you wonderful online shopping!