The 670MBX is a mains powered device with alkaline battery back up. The alarm also incorporates an alarm pause facility for easy silencing of non-emergency alarms. Up to 12 compatible smoke and heat alarms can be linked for simultaneous warning. Features * 230V - Mains Powered * Battery Included * Alarm Pause Button * Low Battery Warning * Multi-alarm Interlink * LED Operating Indicators * Alarm Source Indicator * Sensitivity Test Button * Mounting Base Plate * Push-fit Connector - Easy to Install * 5 Year Guarantee * BS EN 14604: 2005