Sig Sauer ROMEO 5 XDR red dot sight. It features motion activated illumination, 2 MOA dot with 65 MOA circle reticle, 10 illumination settings (8 daylight, 2 night vision), water proof, fog proof, and a 50,000+ hour battery life. This comes with a M1913 picatinny low mount riser as well as a 1.41-inch co-witness riser.