Technical Parameters: Operating voltage: DC 9V (9V alkaline battery) (ship without the battery) Alarm sound pressure: 120dB Induction method: vibrating alarm Start delay: 15 seconds Alarm delay: 30 seconds Installation: Magnetic back can also be hung Dimensions: 90 x 55 x 27mm Instructions: Set the toggle switch to the alarm "ON" position. The red indicator light will fade and turn off after 15 seconds. In alert mode, when vibration or impact is detected, a 120dB alarm will sound immediately. The alarm duration is approximately 30 seconds. This product can be placed in the desired security location. It features a magnetic back and can be attached directly to metal surfaces. Material: plastic Color as shown Package Contents: 1 x Vibration Detector Only the above package content is included; other items are not included. Note: Due to light reflection and differences in display screens, the color of the item in the picture may vary slightly from the actual product. Measurement error allowance is +/- 1-3cm.