LZOS Litkarino ТУРИСТ-ФА / TOURIST-FA Lens adapter

This is the rear part of a Soviet (or Russian) photographic lens for medium format cameras (such as the Kiev 60/6C) or large format. Function: The Turist-FA is not a lens in the strict sense, but an optical extension tube (or adapter) used for macro photography or magnification.
It is typically mounted between the camera body and the main lens to increase the effective focal length and allow very close focusing (macro).
• Mount: The large black and white knurled ring (visible in the first image) is the mount that connects to the camera body, often of the Pentacon Six (P6) type or similar, common on Soviet medium format cameras like the Kiev 60.
So, in summary, the object is an Optical Adapter / Macro Extension Tube called Turist-FA, of Soviet origin.