If you want something that'll shout when trouble shows up, the Bosch Smart Home Outdoor Siren does the job nicely. It blasts out a 100 db alarm with 3 volume levels to choose from, warning intruders to stay away. And it works on mains, solar panel or the built-in battery - so it keeps going even in a power cut.Good to know- The flashing LED makes sure people spot the alarm even if they miss the sound- Connect to Bosch Smart Home app for easy setup and control from your phone- Two way tamper protection means the alarm goes off if someone tries to mess with it, so it's harder to tamper with