$28 3 WHEELS STAIR CLIMBING CLIMBER CONVERTIBLE FOLDING HAND TRUCK 3D model by SURF3D. Available on CGTrader with 1088058 polys and 810130 vertices. Check it out on CGHub.
STL (Stereolithography, filesize: 51.9 MB), OBJ (OBJ, filesize: 107 MB), DAE (Collada, filesize: 170 MB), SKP (Sketchup, filesize: 14.5 MB), GLTF (glTF, filesize: 31.4 MB), 3DM (Rhinoceros 3D, filesize: 23.8 MB), 3DS (3D Studio, filesize: 30.1 MB), DWG (AutoCAD, filesize: 15.4 MB), FBX (Autodesk FBX, filesize: 31.8 MB), BLEND (Blender, filesize: 94 MB), IGE (IGES, filesize: 16.2 MB), SAT (3D ACIS, filesize: 56.7 MB), MAX (Autodesk 3ds Max, filesize: 183 MB), STP (STEP, filesize: 8.33 MB)