This product is easy to install， simply pasted on the host machine door Vice Admiral pasted on the door or on the two windows ， auxiliary machinery arrow mark aligned with the host side . When someone illegally open door or window when ( main and auxiliary parts separated more than 10mm)， the alarm will be issued > 90db siren to warn the intruder to leave. They have to open the door when the window switch can be controlled . Use 3 × 1.5vlr44 button batteries ( included Pat machine ) . The security alarm on the door or window ， the thief want to open the door or window ， the alarm will sound an alarm immediately ， the switch can be turned off when not in use. Application of magnetic induction alarm control technology ， long life ， easy to install . Using adhesive paste ， no screws ， can be pasted directly use ! Without damaging household items ! ( Also can be installed in the cafe computer chassis， computer hardware to prevent theft ) Usage: can be installed on windows and doors， a switch ， when the switch is turned on ， if the doors are opened ， a loud alarm will sound . Sleep at night or when not at home ， when out of the office ， the alarm switch is open ， the security alarm . Usage: alarm consists of a large and a small piece composition， the alarm size pieces were attached to the sides of the gap in the middle of two windows ， large and small pieces arranged in parallel ， middle gap size pieces so as not more than 5 mm ( can refer to the packaging looks good paste ) ， small pieces with an arrow ， the arrow in the opposite direction to the large and bulky parallel posted on the good ， to security， closed the window ， ? Chi  ň  epiphyseal  Dian pure ? ， if thieves push the window ， as long as the window opened ( ie alarm large and small pieces of more than one separate 5 mm ) ， the alarm will send a strong warning sound ， the master of the house will take immediate action ， the thieves will be caught on the spot live or fled.