Model Stand Detail Photo - Casters  
Two types of permanent caster configurations are available: Type 1: Fixed Position Side Mounted and Type 2:  Adjustable Height Bottom Mounted.      Type 1 are installed on all Model Stands on the narrowest dimension of the platform to make it easy to move platform from room to room, through doorways, into elevators and such, when the platform is tipped up into a vertical position.
Type 2 are optional and can be enabled or disabled with a large screw mechanism, as shown below.