1. Simple operation: test immediately after power-on, one-key operation for test, simple and easy to use. 2. Buzzer alarm: when the detector detects metal, the buzzer will sound an alarm. 3. Red light indicator: when metal is detected, the indicator light is red. 4. Angle transformation: the probe rotates 180, suitable for more scene measurement. 5. Long-lasting battery life: using smart power-saving technology, low power consumption and long battery life. Specification: Model: DM3004A Expanded size: 394*140mm Battery: DC9V 6F22 (not included) Working temperature: -10-50 Current consumption: less than 3mA LED indicator: working and low battery prompt Alarm: buzzer sound/LED alarm Applicable environment: high-speed rail/airport/subway/hospital/venue/sports meeting, etc. Note: Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you Please allow 1-2cm measuring deviation due to manual measurement. 1 x Metal Detector 1 x User Manual