Although both a mobile Office Trailer and a ground-level office (GLO) are used as an office during construction and are a great way to add office space on-site, they have some differences. An Office Trailer is on wheels and can be transported from location to location using a tractor-trailer or an authorized vehicle with a ball hitch lock. An Office Container is made out of a steel ISO shipping container and provides a rugged exterior for an additional level of security. An Office Container must be empty but can be moved by Dear John Inc.