Features: Ultra-thin design for installation in new aluminum window. The product has two parts, one part is the main unit and the other part is the magnetic stripe. When the host and receiver leave more than 8MM, the alarm will be given. When the alarm is too low, the indicator will flash red to remind you to replace the battery in time. Installed in the office and at home with doors and window, it sends out a 120-125 decibel sound through a magnetic stripe sensor to scare away thieves. Long service life and stable performance. Specifications: Condition: Brand New Color: Shown as Picture Material: ABS Battery: 3 * LR44 (Included) Body Size: Approx. 7.5*4*1cm/3.0 * 1.6 * 0.4 in Magnetic Strip Size: Approx. 3*1*1 cm/1.2 * 0.4 * 0.4 in Package List: 1 * Magnetic Door Alarm 2 * Adhesive 1 * Instruction Manual 1、Ultra-thin design for installation in new aluminum window. 2、The product has two parts, one part is the main unit and the other part is the magnetic stripe. When the host and receiver leave more than 8MM, the alarm will be given. 3、When the alarm is too low, the indicator will flash red to remind you to replace the battery in time. 4、Installed in the office and at home with doors and window, it sends out a 120-125 decibel sound through a magnetic stripe sensor to scare away thieves. 5、Long service life and stable performance.