The Sig Sauer ROMEO 5 compact red dot sights provide civilians and armed professionals a robust 1x aiming solution for any situation. The sights are parallax-free so point-of-aim and point-of-impact remain the same. Unlimited eye-relief allows you to acquire the aiming point and the target regardless of the position of your eye behind the sight. The readily available CR2032 battery is side-loading, allowing for quick battery replacement (featuring 50,000 hours or more of life). Dependable waterproof (IPX-7 rated for complete water immersion up to 1 atmosphere) and fog-proof performance.Backed by the SIG Sauer Electro-Optic Infinite Guarantee.