That one is from XS Sight Systems (the Big Dot people). Got it on Amazon.Thanks yamadog 35. Who makes that particular sight?
I put that exact sight on my Gen2 Sub2K. I could not see the stock black post front sight against a black bullseye at the range. I got the yellow chevron with the tritium dot. Mounting is a little tricky - watch the spring underneath the sight. It wants to leave and start a solo career. Also the Blitzkrieg has to go a full rotation to present the correct side to the shooter. After a slight adjustment up in elevation I was consistently in the 10-ring.I'm considering putting one of the chevron front posts on from Blitzkrieg.
It might trade off a little bit in precision, but using a 6 o'clock hold it should still work pretty good within the reasonable range for a 9mm carbine.
Those are nice. Will be hard what one to pick??? What one is your favorite...You need the Blitzkrieg tool - a standard AR adjustment tool isn't a good fit with their sight. You can order a sight and tool as a package.