Vintage INV 925 Italy Silver Mariner Chain 19" 6mm x 10mm Links VG Marked

This vintage silver chain is used but in very good condition. There is light scuffing/scratching from use. It is marked 925 Italy and INV on both sides of the clasps. I could not find any information on the INV mark. It measures 19" from end to end. The links are 6mm wide x 10mm long. It comes with a gift box.