B
bugsy
if you've got an existing alarm stick a volt free relay on the existing sounder output instal a banshee siren .
If it dosent stop'em ( if your close enough long enough some can make your ears bleed ) at least everyone in a half mile radius will know about it
If it dosent stop'em ( if your close enough long enough some can make your ears bleed ) at least everyone in a half mile radius will know about it