Aimpoint 9000 Red Dot Sights offer fast aiming with a heads-up design that allows the shooter to keep both eyes open and on target. The bright red dot is created with a CET diode with 10 different brightness settings and will shine for over 50,000 hours on a single lithium battery (included). Unlike many other red dot sights, these Aimpoints feature a true 30mm tube, so they can be mounted with most 30mm scope rings. Covered under a 10 year limited warranty.