Abstract: An audio-visual device that combines synchronized programs of narration and music with direct viewing of illuminated 35mm stereoscopic transparencies presented in automatic progression. The device features four innovations in particular: 1. Endless-loop reels in which the stereo mounts themselves serve as the basic "hardware," requiring no belts, discs, frames, drums or cylinders for support, and simplified for expeditious removal and compact storage to solve the many problems of inventory and program change-over. 2. Jam-proof transmission for advancing slides intermittently, comprised of a sprocketed drive wheel and a 4-vane "paddle-wheel," with meshing cogs so spaced and positioned as to remain constantly "in gear," never "out of gear." 3.