FBI recently approved use of ROMEO4M Red Dot Optic. While it is unclear if the optic performed on par with its competitors, it means it has met FBI's requirements. While many pointed out that it looks like Holosun, some people mentioned that the particular model was not made in China, and quality is different.
This is a big victory for Sig Sauer as they brought in some people from Leupold and has been working on a system of accessories package.
It features 2MOA dot and 65 MOA circle, similar to EOTechs
From: The Firearm Blog, SIG Forum