Heavy hauler trailer
Heavy hauler trailer means a trailer which has one or more of the following characteristics, but which is not a container chassis trailer: (1) Its brake lines are designed to adapt to separation or extension of the vehicle frame; or (2) Its body consists only of a platform whose primary cargo-carrying surface is not more than 40 inches above the ground in an unloaded condition, except that it may include sides that are designed to be easily removable and a permanent front end structure as that term is used in 393.106 of this title.