Best flush mount/descreet PIR?

I am looking for a PIR that is minimal. I am having trouble finding any with google.   
 
 
It looks like there is a flush mount European product from a company called Dalmers.  Does anyone have experience with that device or another that is unobtrusive?

Visonic Spy or clip
 
Keep in mind, a PIR generally will require adjustment and honestly the performance of a dualtec outweighs the aesthetic issues. Once false alarm or having to rework your flush or concealed unit.....or when they're no longer available and you require replacements.
 
If you really want unobtrusive interior detection, stress sensors are the way to go, albeit more expensive.

Great advice, thank you.   Aesthetics is one of the most important things for me, but you have given some good direction on what to research next.  

I'll second Visonic Clip.  Not surface mount, but they have a very small footprint.

Visonic Spy. I put these in the ceilings of our hallways during construction. painless.