Installing Motion Sensors

Hi,

The manual says to install the motion sensors between 4-5 feet off the ground. But I have seen many youtube videos where these motion sensors are being installed much higher than 5 feet.

So exactly how high should I install these motion sensors? I installed one at exactly 5 feet and it looks very low and out of place on the wall. My old existing wired alarm system has the motion sensor installed around 8 feet off the ground.

Please advise.

Thanks