Very handy slide viewer from Germany used for slides 4×4 or 5×5 (including widow). This system is called the Journal24 and used a huge double lens system that works with daylight or can be used when slides are put on your board with backlight. Hardly used from the 1960’s in the original box. It measures 9,5 cm or 3 5/8 inches. Check the video for the real manly way to few your old slides.