Elmo Auto Changer Slide Projector & Color Transparencies Retro Film accessory made by ELMO Co., a Japanese company known for its high-quality audiovisual equipment. Untested however color transparencies included.. The Auto-Changer was typically used in the mid-20th century for automatically advancing film reels in projectors-commonly Super 8mm or 16mm formats. popular in schools, libraries, and home movie setups. #RetroFilm #8mm #ElmoAutoChanger