In this paper we present the results from four empirical studies where we investigate the most appropriate devices for high-ranking emergency leaders - termed commanders in this paper - working close to the scene of incident, usually outside. The studies apply different methods including interviews, questionnaires and usability tests to investigate the technology used by commanders in the agencies today, their motivation for using new technology, as well as their needs for new devices. Three of the studies involve commanders from the police, the ambulance service and the fire and rescue agency in Norway. Devices with different screen sizes ranging from 4,3" to 40" were used or discussed in the studies. The main conclusion from all the studies is a very clear preference for tablets. We did however identify difference between the agencies regarding the preferred size of an "ideal" tablet, as well as wishes for using more than one device.