Didn't see the coverage, but the smallest ones I am aware of are the:
Jpoint - http://jprifles.com/1.6.1.php
Burris Fastfire - http://www.burrisoptics.com/fastfire.html
Doctor Optic - http://www.analytik-jena.de/en/DOCTER/Products/Red-Dot-Sight__230/
or
Trijicon RMR - http://www.trijicon.com/user/parts/parts_new.cfm?categoryID=13
There are probably others. In fact, the Trijicon model pictured here with the Doctor looks a lot like the Jpoint: http://centurionstore.com/trijicon-red-dot.htm I didn't see it on Trijicon's website.
I have seen a few USPSA open guns running slide-riding Doctor's. The Jpoint, I believe, was previously sold by a different manufacturer under a different name and had reliability issues. I am told that JP fixed the issues and brought them back out. I have only seen them as close range or backup sights on scoped AR's.
Jpoint - http://jprifles.com/1.6.1.php
Burris Fastfire - http://www.burrisoptics.com/fastfire.html
Doctor Optic - http://www.analytik-jena.de/en/DOCTER/Products/Red-Dot-Sight__230/
or
Trijicon RMR - http://www.trijicon.com/user/parts/parts_new.cfm?categoryID=13
There are probably others. In fact, the Trijicon model pictured here with the Doctor looks a lot like the Jpoint: http://centurionstore.com/trijicon-red-dot.htm I didn't see it on Trijicon's website.
I have seen a few USPSA open guns running slide-riding Doctor's. The Jpoint, I believe, was previously sold by a different manufacturer under a different name and had reliability issues. I am told that JP fixed the issues and brought them back out. I have only seen them as close range or backup sights on scoped AR's.
