Everyone seems to love their PS90, except for the factory optical sight. After trying several rail systems on my P90 in order to replace the crappy optic with my Trijicon Reflex, I discovered that all the aftermarket rails caused my Reflex sight to sit way too high obove the gun. With the sight 3" above the barrel, it was difficult to obtaion a good sight picture while maintaining a good cheek weld on the rifle. Additionaly, the paralax between 50 and 100 meters made the holdover excessive at best. I even tried out the new TR version with the factory flat top. To my surprise, I found the optical rail on the TR to be almost the same height as on the regular version. After some milling, cutting and welding, I came up with the new "ultra low" flat top you see in the pic. Now my Reflex sits exactly at eye level, while still allowing a normal cheek weld.