The rear oval sight has been designed with the perfect built-in lead; if the bird's wings are horizontally touching the right and left compass points you can rest assured that it is approximately 30-35 yards away which is inside the kill zone range of most shotguns.The base is made of T-6 aircraft-grade aluminum; the orange ring is molded from optical Lexan and incorporates large compass points for trouble-free viewing and easy target acquisition. This sight is fully adjustable for windage and elevation.