The file 'Helios 44-2 Pentax K10D Locking Ring 3D Printer Model' is (STL) file type, size is 43.5KB.
A locking ring that mounts onto the lens and engages with the pentax locking pin. I have the m42 adaptor spring removed and the adapter just screwed onto the lens.
You will need m3x20mm bolt and a nut.
