TDC Standard Stereo Slide Projector - Model 116 - Refurbished/vintageTDC Standard Stereo Slide Projector Model 116 vintage Reconditioned fully warranted Manufactured in Chicago by the Three Dimension Company beginning in the early 1950s, their sales were so successful that the Chicago firm of Bell & Howell, a long established projector manufacturer, purchased the Three Dimension Company to expand their projector line Bell & Howell continued to produce the stereo projectors under the TDC brand name, continued to produce