For more information videos and installation guides on the dsc alexor alarm system click herefor the alexor brand store the dsc alexor wireless door or window contact installs and connects with the rest of the system in seconds and includes all batteries simply stick the magnet and detector to the door or window frame using the supplied sticky pads and you are ready to gobuilt in reed switchnormally closed external contact input1 lithium battery includedreliable 433 mhz technologycase and