At a Glance:  Easy drop-in installation Instinctive sight centering Full function of rear windage and elevation controls  Improve your target acquisition with this affordable drop in upgrade!  When shooting round steel targets it is advantageous to have a round rear sight. The circular plate fills the arc of the sight to make for easy target acquisition. Made of CNC machined aluminum for long lasting durability. The "Eagle Eye" Rear Peep Sight For Williams Fire Sights is anodized matte black, to absorb light and reduce glare. This easy to use upgrade allows the shooter to intuitively center the front sight in the aperture, resulting in clear and faster front sight focus.