The 42T weight class is a very small step up from the 35T. The most obvious difference is the addition of a gooseneck extension. This extension gives the necessary swing radius to fit a tridem truck. The trailer is 53 ft with the extension flipped up. This allows for a longer deck length at legal overall length.
This model of trailer may be sold with a modular bogey to allow for different deck sections or deck inserts to be added.