This three dimensional model allows students to study our solar system -- looking at planets' (and a dwarf planet's.. Sorry Pluto) relative sizes and colors. Planets can be set by month to show their relative positions. The 5.9" sun is supported on a sturdy base with the outer most (dwarf) planet being 18" from the sun. An illustrated guide is included with planet position tables. This demonstration requires a external power supply that is equipped with 4mm banana clips. Power supply or wall plug / adapter not included.