TECHNOLOGY DECT technology for secure connection and clear sound without interference BABY UNIT Operates on mains power 5 lullabies with 5 level volume setting Room temperature sensor Speaker/microphone for 2 way communication with parental unit Night light PARENTAL UNIT Uses rechargeable batteries for up to 14 hours active monitoring time before recharging LCD for room temperature monitoringSpeaker/microphone for 2 way communication with baby unit 5 volume levels and volume off Low battery audible alert Out of range audible alert