This series was first documented by Irene Thornburg in her second reference book on salt and pepper shaker series. The complete series consists of four sets - each set consists of animals sitting on a swing suspended by a tree trunk stand.
Each set is impressed "Pat TT" and some have a "Made in Japan" sticker. Each animal shaker has 2 pour holes, while each stand has 4 pour holes. Circa 1950s.