Aico EI141 Mains ionisation smoke detector and alarm. Unbeatable deal at just £12.90. Interconnects with other Ei mains powered smoke and heat alarms. Responds quickly to fast flaming fires; Supplied complete with 9v alkaline battery; Hush button for false alarm control; Separate mains and warning LEDs; Protective dust cover included; all this and a 5 year guarantee!