This disentanglement puzzle consists of three intertwined metal rings. A paper card gives instructions on how to separate them. A mark on the card reads: No. 878. THREE RINGS PUZZLE. The text and figures, as well as the model number, correspond to those in a 1920 A.C. Gilbert catalog, hence the maker and rough date assigned.
Reference:
A.C. Gilbert Company, Book of Instructions for Use with Gilbert Puzzle Parties. . ., New Haven: A.C. Gilbert Company, 1920, p. 3. A copy of this booklet is online at gamearchives.org, accessed July 26, 2017.