$6 Square Rose Mortice Door Knob 3D model by Polygate. Available on CGTrader with 3066 polys and 3060 vertices. Check it out on CGHub.
OBJ (OBJ, filesize: 62.6 KB), FBX (Autodesk FBX, filesize: 138 KB), MAX (Autodesk 3ds Max, filesize: 3.01 MB), 3DS (3D Studio, filesize: 40.5 KB), C4D (Cinema 4D, filesize: 120 KB), BLEND (Blender, filesize: 155 KB), MA (Autodesk Maya, filesize: 112 KB), MEL (Maya Mel Script, filesize: 112 KB)