Kilfit Makro Kilar Skylight 0x Filter for 4cm f/2.8 Macro Lens VERY RARE V17

This very rare Kilfit Makro Kilar skylight 0x filter is for use with the Kilfit Makro-Kilar 4cm (40mm) f/2.8 macro lens. It has a couple of very tiny nicks on its glass, but nothing major.