Well built but not without flaws - Trijicon RMR Type 2 RM01 LED 1x65mm 3.25 MOA Red Dot Sight

Installed on an FN 509 Tactical. This is a great optic for co-witnessing with suppressor height sights. The 3.25 MOA dot is just the right size. If you hold both buttons for a fraction of a second you will enable automatic brightness which works very well. I did have some issues with parallax, but I believe with a little training I can learn to work around it. The nice thing about having suppressor height sights is that if the optic fails you'll still be on target. On my other guns I run an RMR without co-witness and I'm still on target. The co-witness reveals how if your head isn't directly in line with the pistol, the dot dances around a bit (parallax), however, the shots were still on target just not a tight grouping. I feel the RMR is faster than irons and with a little training you can compensate for the the parallax issue.