TECHNOLOGY 2.4GHz FHSS technology for secure connection and clear sound without interference BABY UNIT camera with motorised pan & tilt infrared for night use digital zoom and standard & projection night lights. Operates on mains power 4 soothing sounds Temperature sensor speaker/microphone for 2 way communication with parent unit. Wall mountable. PARENT UNIT 2.8? colour display High capacity rechargeable battery pack for up to 19 hours active video monitoring time before re-charging. Room temperature monitoring Speaker/microphone for 2 way communication with baby unit Sound activation mode low battery audible alert out or range audible alert. Can monitor up to 4 baby units ( with the purchase of additional baby units).