If you've ever been stuck behind a slow-moving semi-truck with nothing to do, you may find yourself wondering what the little door on the trailer is for.

So, what exactly is a semi-trailer? It's a type of trailer ... and chemicals, you need a refrigerated trailer -- also known as a reefer trailer. This type of trailer is designed with a built ...

New options from the manufacturer include CenterSeal load partitions for refrigerated units and captive-beam securement for ...

the door on the back of semi-trailers is used for ventilation and can often be found on refrigerated trailers, or "reefers." When opened, the load can get proper ventilation while the truck is in ...