1.can inform you within 1km if the thief stolen your car 2.no need change the car or bicycle ... with keys is infrom people alarm if having the thief stolen your product2.the concealment is very good ,now i can ... hide the back of door ,can protection your home cannot stolen , if you put in the car ,can protection your ... 500-1km wireless inform distance is ok ,some thief stolen your car ,you can get him!