In all the pics I’ve seen it looks unlike any other sight I’ve seen. I really like it. What is it? Kind of like a 10-8 sight with a tritium dot, and slanted sides.
DAN WESSON says that it is their sight.
The ECO wears tritium night sights with our tactical ledge sight on the rear of our lightweight 3.5” slide.
…but they say Trijicon.

They are Heinie Straight Eight Tritium Sights. I like them and love my ECO.
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Hm. It looked like it had a U-Notch. Also, I figured the Trijicon labeling only was for the tritium vials.
Square notch on the rear sight.
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They used Heinie for quite a while. Recently switched to their own in house Heinie knockoff from what I hear. Not sure of the changeover date.
Most likely.
The ECO and Specialist have the in-house DW rear sight.
It’s a very nice piece. I think they should make all their pistols with them.