Tower Mobile Message Center. The Tower Mobile Message Center: The Tower Message Center is a mobile free standing letterboard that is as attractive in appearance as it is convenient to use. Its sleek black contemporary design offers a stylish way to visually display information and messages. Moving the 56 high Tower is simple thanks to its built-in wheels designed into its base. The black changeable letter surface offers you the space and flexibility to create messages that people can't miss. The Tower's L-shape provides an extremely stable base that also serves to protect it from jostling. Ships via UPS. A set of 3/4 letters numbers and characters is included. FREE SHIPPING!