magnetic sensor wireless burglar alarm for doors and windows

1~5PCS New Longer Door Window Wireless Burglar Alarm With Magnetic Sensor Home Safety Wireless Longer System Security Device Features: Easily mounted by adhesive 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) Specification 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 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 Specifications: Door Window Wireless Burglar Alarm Home Safety Wireless Longer System Security Device Package Included: 1 x Alarm Unit 1 x Magnetic Sensor