 The Class locomotives could be distinguished from the other series by the air conditioning units mounted on their cab roofs and initially, when it was still a feature unique to them, by their running board mounted handrails.At some stage during the mid-1980s, all Class , and locomotives had saddle filters installed across the long hood, mounted just to the rear of the screens behind the cab on the sides.Since then, Class locomotives could be distinguished from the older models by the absence of the saddle filter.