"Ten-year radio module Ei600MRF for ten-year smoke and heat alarmIndependent power supply: permanently installed 3-V lithium battery, at least 10+1 years' service lifeTool-free assembly: Plug in the radio module by handHouse coding for interference-free communication with all system componentsEasy Entry function facilitates the integration of new units into existing radio systemsBuddy Missing function indicates the removal of a unit from the radio systemTested quality certified according to VdS 3515 (G211009)"