Fits 1/4", 5/16" and 3/8" ribbed guns. Machined aluminum. No tape required. 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 your bird is approximately 30-35 yards away which is inside the kill zone range of most shotguns. 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 with the simple turn of a key. The primary objective of this sight is to force the shooter to anchor their position with the correct posture on the weapon during engagement. This serves as a tool for newcomers to the sport and helped seasoned veterans to re-focus on the core principals of shooting when years habit have taken over.