Check out Optical scope X20 power 3D model on CGTrader for $15. High-quality mesh by khaleel-89: 71806 polys, 124389 vertices.
SKP (Sketchup, filesize: 11 MB), FBX (Autodesk FBX, filesize: 12.5 MB), F3D (Autodesk Fusion 360, filesize: 1.33 MB), STL (Stereolithography, filesize: 6.85 MB), IAM (Autodesk Inventor, filesize: 56.5 KB), 3DS (3D Studio, filesize: 3.64 MB), DWG (AutoCAD, filesize: 11.9 MB)