A small enclosed trailer is a smaller variant of a typical enclosed trailer that normally features a single, barn-type, rear door. Enclosed trailers serve to transport cargo while protecting it from the outside elements, such as wind, rain or snow, unlike open trailers.
Enclosed trailers are usually heavier and more expensive than open trailers, because they are closed on all sides. They provide more aerodynamic drag, due to the extra weight. However, enclosed trailers include an additional layer of security by serving as portable storage units that can be locked. As of 2014, enclosed trailers cost between $1,600 and $5,000 on average, although the price can go much higher.