Also, where the MFC-L3770CDW comes with a 30-sheet multipurpose tray for printing envelopes and other media, the MFC-L3750CDW has only a single-sheet override tray. At 16.3 by 16.1 by 18.7 inches and weighing 51.5 pounds, the MFC-L3750CDW is slightly smaller and lighter than its higher-end sibling.