Listing is for five vintage mercury glass clip on bird figure Christmas tree ornaments. I’ve seen these listed with the tails being described as spun glass tails, which could mean fiberglass which I believe these are or it could mean Glass mixed with other components to create these details. Please see all photographs as they are part of the item description and message with any questions that you may have. Please note that there is some roughness or chipping to the edges of the tails of the dark red bird and the green bird. I’ve tried to show close-ups of this chipping. Otherwise, they are in overall very good vintage condition. They aren’t unmarked as to maker but I believe these will probably made in Germany or Czechoslovakia