Kaiser Diascop Mini 3 is a compact slide viewer measuring approximately 10cm, front to back and 6.5cm high. Perfect for use with 5x5 (2x2inch) frames, mounted slides, it has a clear, glass screen, which is magnified 3X to give a more accurate view of the image. The 2.5v lamp is a compact, screw-in type and the unit is powered by 2x 1.5V AA sized batteries (not included). The slot for the slide is on the top of the unit in the middle and the batteries and lamps can be changed by lifting off the top and then clicking it back into place. manufactured to a high standard, as you would expect from Kaiser, this is a really neat unit for checking over old slides and helps with storage and cataloguing.