Made for Amazon Motion Sensor for Echo Flex Price: £14.99 (as of 25/09/2020 01:16 PST- Details)

Certified “Made for Amazon” all-new Motion Sensor designed exclusively for Echo Flex. Echo Flex sold separately by Amazon.
Create Routines: Using the Alexa app, create your own routines that are triggered when motion is detected. Customize Alexa messages like “Welcome Home” or “Motion Detected in Living Room” when motion is detected.
Smart Light Control: If you have a smart light or smart plug connected to the Alexa service, you can create a routine in the Alexa app that will enable it to automatically turn on when motion is detected (and off when no motion is detected for a period of time that you specify).