Check out MOUNTED EXTENDED TELESCOPIC BOOM LONG REACH MOBILE CRANE ARM JIB 3D model on CGTrader for $25. High-quality mesh by SURF3D: 128321 polys, 126260 vertices.
STL (Stereolithography, filesize: 6.12 MB), OBJ (OBJ, filesize: 12.2 MB), DWG (AutoCAD, filesize: 36.6 MB), SKP (Sketchup, filesize: 17.6 MB), 3DS (3D Studio, filesize: 4.14 MB), IGE (IGES, filesize: 65.7 MB), 3DM (Rhinoceros 3D, filesize: 69.5 MB), STP (STEP, filesize: 30.2 MB), OTHER (Other, filesize: 30.2 MB), BLEND (Blender, filesize: 12.2 MB), SAT (3D ACIS, filesize: 42.1 MB), FBX (Autodesk FBX, filesize: 3.97 MB), MAX (Autodesk 3ds Max, filesize: 44.4 MB)