I have been looking at these for a while, and took the plunge on Prime Day for a good price. this little beauty is awesome.
Small with a magnetic base to fit on a small bracket included, and runs on 2 x AAA batteries. the instructions say they will last for 2 years, so I will have to wait to find out :) Piece of cake to setup and seems to work reliably 100% off the time so far. I think I need more of these now... I will have to wait till they are on special again.
Other reviewers talk about a temperature sensor and lux sensor in the unit, it is not documented anywhere but yes they exist as long as you are using Apple Home. I am using Alexa and these sensors cannot be accessed as yet
Change the way you control light at home with the Philips Hue Motion Sensor. Light up a room simply by walking in and control the intensity by the time of day, such as a gentle, warm nightlight to help you navigate your home at night. Battery powered, wireless, and installation free, this Hue Motion Sensor requires the Hue Bridge (sold separately) to work, connecting to your Hue system with control via the Philips Hue App. Place it anywhere in your home including your hallway, bathroom, kitchen, and more. The integrated light sensor saves energy by detecting when rooms are vacant and automatically turning off lights. Make it part of your Hue home lighting system with Hue accessories (sold separately) such as the Hue Tap or Hue Motion Sensor. Control by voice with Amazon Alexa, Apple Home Kit, and Google Assistant. Connect it with your Nest or Samsung SmartThings system for smart home control. Each kit includes one Hue Motion Sensor with two AAA alkaline batteries, a magnet, screws, a manual, and a two-year warranty.