1.This front and rear mechanical sight has excellent adaptability to any rail. Fits for 20mm Picatinny / Weaver Rail. Slotted screws attachment. One piece streamline design. 2.The front and rear sights of the D-type mechanical sight are made of high-quality materials, which have excellent durability and impact resistance. Made from 6061 aviation grade aluminum material and subjected to hard coating anodizing treatment. 3. and streamlined design ensures a reliable and deployable sight. 4.The design of the front and rear mechanical sights emphasizes a user-friendly operating experience. The adjustment of the sight is very simple, just lightly rotate it to complete. Whether you are a professional or a beginner, you can easily get started. At the same time, the design of the sight is simple and elegant, in line with ergonomic principles, and comfortable to grip.