Cheapest its been I believe.
Triggers your hue lights when motion is detected; automatically turns on soft and gentle night light for you or your partner without having to click a switch on
Program the sensor with the Philips hue app to control hue lights to any tone, any level as you need it without touching your smart devices
Place it anywhere - portable sensor to work from anywhere in your home; 2 x AAA alkaline batteries included (typically lasts 2-3 years)
Program your sensor to turn on lights to a soft tone during the night to reassure your kids walking at night
Works with a Philips hue bridge; connect up to 10 hue sensors to your hue bridge and program lights to suit your needs
Control your Philips hue lights with your voice on Amazon Echo, Amazon Echo Dot and Amazon Tap