Mk.IV.1 Modelviewer (2005). Neon light illuminated, 230 V. Rails can carry current from external power supply via sub-miniature 2-pin connector. Length 640 mm, width 330 mm, total height 180 mm, length of track 620 mm.

Mk. IV.1.1 Modelviewer (2005). Neon light illuminated, 230 V. Rails can carry current from external power supply via sub-miniature 2-pin connector. Baseboard made of maple wood, length 565 mm, width 265 mm, total height 145 mm. Length of track 615 mm, maximum load 10 kilograms.

Mk.IV.2 Modelviewer (2005). Not illuminated. Turns manually in a circle. Wheels made from ball bearings with rubber tyres. Rails can carry current from external power supply via sub-miniature 2-pin connector. No baseboard. Length 780 mm, width 330 mm, height 145 mm.