Description:Door Window Wireless Burglar Alarm Home Safety Wireless Longer System Security Device Easily mounted by adhesive tape to window or door. Magnetic sensor switch detects entry protecting your home or office whether you are in or out. Warning door/window sticker is supplied free in package. Operating by 2xbatteries(not includ) Specifications:Open the battery cover,Match positive and negative signs and Insert2 triple A batteries correctly, close the battery cover Fix the main unit which has on-off switch at the side of the door&window. Attach the bar magnet to door fram/window frame with the arrow aligning with the referenc line of the main unit. Switch to"ON" position of the main unit so as to be in alert state,it will give an 90bp alarm if the magnetic senor has been separated fron the alarm device when someone opens the door/window. Please turn off the switch when you don\'t need Remove the batteries to prolong the lifetime of the product/batteries if it will be set aside for a long time Package Included:1 x Alarm Unit 1 x Magnetic Sensor Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-Dadangjia