1ere order with this seller, very serious because I received the package. Very well pack, and frankly jen and seen anti flying bar but the one? These steps of shit ATTENTION her and super strong, strengthen and the sounds of alarm and very good. I expect a 2eme order from this seller but I think to recommend others for the family. As soon as you engage the flying block? If the thief forces the bar to several recovery? A small red light flashes and after its sound. AAA battery by cons, I am very satisfied with its change of basic bar. Thank you Aliexpress