Bullets three Free low-poly (Polygon mesh 3D model) is available on CGTrader for free. Original author: PackDev. Specs: 700 polys, 700 verts.
STL (Stereolithography, filesize: 36.6 MB), OBJ (OBJ, filesize: 36.6 MB), DAE (Collada, filesize: 36.6 MB), FBX (Autodesk FBX, filesize: 36.6 MB), USDZ (USDZ, filesize: 36.6 MB), GLTF (glTF, filesize: 36.6 MB), C4D (Cinema 4D, filesize: 36.6 MB), MAX (Autodesk 3ds Max, filesize: 36.6 MB), BLEND (Blender, filesize: 36.6 MB), UASSET (UnrealEngine, filesize: 36.6 MB), UNITYPACKAGE (Unity 3D, filesize: 36.6 MB), ZTL (Zbrush, filesize: 36.6 MB), SPP (Substance Painter, filesize: 36.6 MB)