The humanoid Mech models had an average size of 30 cm, the in-scale humans were about 2 cm. One of the features of the models (excepting the Human and Grelon miniatures) was that they were not static, but had fully movable joints and removable equipment. Because of the complexity, details and parts they can be challenging and require adult skill level even though they were sold with "ages 12 and up" on their packaging. Experienced modelers found them challenging, especially the Humans and Grelons.