There is no alarm function for this holder. This configuration is mainly designed for reducing cost, while to some extent, it is a deterrent to theft. There is a pc of spring wire assembled to this magnetic JB-1128 holder. Pull out this spring wire, its maximum full length can be 2 meters. Then loosen it, it can get back to the original length.
Provided you have special requirement, we can also make live sensor for this JB-1128 magnetic holder for you. Thus the holder can be connected to alarm system to realize alarm function. Once the wire is cut or the sticker on the sensor is peeled off, it will then give alarm immediately.