The panel also shows the location in the activated gadget, which makes it simpler for emergency responders to rapidly locate and address the issue. The SBBRKSM easichange® kit replaces the discontinued BRK 660MBX optical and 670MBX ionisation smoke alarms and fits on to your existing BRK twist-in good shape alarm https://www.firesense.co.uk/type/addressable-fire-system/addressable-fire-alarm-control-panels/