Eotech EXPS3 1x 50mm Holographic Red Dot - Circle 1 Dot - The "E" is for "Extreme." The EXPS3 offers true 2-eyes-open shooting and a 7mm raised base that still allows for iron sight access. It features easy-to-adjust side buttons and an adjustable, locking, quick-detach lever for easy attachment and removal. Its night vision-compatibility makes it a versatile choice for day or night hunting.