That is, 3 groups of 4-piece eyepieces, half-five + roof 2-piece prism group, and 3 groups of 4-piece objective lens groups, the imaging is anti-distortion and deformation to ensure clear imaging. The 18.5mm Bak4 prism and phase film are used to ensure the image quality and make the image brighter and more transparent. IPX7 grade vacuum nitrogen filled waterproof,Waterproof design, suitable for daily use, preventing mold and greatly extending the lifespan of the telescope The interior is filled with nitrogen and sealed to prevent the intrusion of water vapor, waterproof standard for 30 minutes at a depth of 1 meter, IPX7 waterproof and anti-fog, no fear of wet and rainy environment. This portable monocular telescope has a calm and atmospheric texture. The ergonomic design allows you to use the telescope with one hand better and quickly focus on the target. Very suitable for outdoor use.