Check out Ball Mortice Door Knob 3D model on CGTrader for $6. High-quality mesh by Polygate2: 1514 polys, 1506 vertices.
OBJ (OBJ, filesize: 30.2 KB), BLEND (Blender, filesize: 102 KB), FBX (Autodesk FBX, filesize: 66.6 KB), MA (Autodesk Maya, filesize: 57.4 KB), MEL (Maya Mel Script, filesize: 57.4 KB), MAX (Autodesk 3ds Max, filesize: 2.79 MB), 3DS (3D Studio, filesize: 17.6 KB), C4D (Cinema 4D, filesize: 99.6 KB)