This set includes 2 advertising thimbles from the 1930’s – 1940’s and an open top thimble which I believe is sterling silver but the hallmark is indistinguishable. The NU-MAID Margarine thimble is celluloid or plastic, it is beige in color with red lettering. The White House Coffee & Tea thimble is stamped inside with the letters B&B St. P. It is made of aluminum. These were advertising premiums. The open top thimble is slightly out of round as shown in the photo.