Dimension mock-up of the newer Trådfri motion sensor. I haven't yet decided on how to mount mine so created this for any holder/stand planning.
Trådfri_motion_sensor_with_tolerances.stl has 0.1mm dimension tolerances for easier use as a detraction piece.

https://www.tinkercad.com/things/f96rM4QrwDA-ikea-tradfri-motion-sensor-mock-up