For more information videos and installation guides on the dsc alexor alarm system click herefor the alexor brand store the dsc alexor wireless outdoor siren with a flashing blue strobe when activated installs in seconds and is weather resistant also unlike most other wireless alarm systems the siren has two way communications with the rest of the system and it will transmit its status so the system is aware of issues such as low battery poor reception or tamper you can connect up to f