* 2.4 GHz Digital wireless link.* High sensitivity.* Voice-activated transmitter.* Powered by 3 + 3 AAA 1.5 V batteries (not supplied), or via the supplied mains power adapters* Range up to 300 metres unobstructed.* Place the child unit around 1.5-2.0 metres from the child.* The parent unit has a belt clip enabling it to be easily portable.