I've never seen another whimsy chain like this one (the making of which completely baffles me!), with the square on every other link sliding from one side of the link to the other horizontally. All carved from one piece of wood and quite finely done. I would guess early 20th century, with a nice dry wood patina; quite elegant and quite lovely.
20"long x 3/4" wide and deep. Very good condition, with no losses, splits or other issues whatsoever, and all the sliding parts slide smoothly.