EAO, the expert for human machine interfaces (HMIs) sets a new standard with the new Series 57, the door opening pushbuttons for public transportation. Especially user friendly are the extra large operating area of Ø 74 mm and the two independently illuminated feedback rings. The additional user benefits of the raised, illuminated symbols and the optional finding tone make this unique “all-in-one” door opening pushbutton the best in class. The optical, tactile and acoustic feedback is unbeatable. The Series 57 is the perfect choice for all train and tram manufacturers and operators.