Trolltune Corporation, with offices in Valencia, California, Cheyenne, Wyoming, and Steinsto, Norway is a developer of several STCs, including various patented air-to-ground datalink, navigational, and gross weight increase STCs. The company maintains excellent relationships with regulatory agencies, including the US Federal Aviation Administration (FAA), Transport Canada Civil Aviation (TCCA), Australia's Civil Aviation Safety Authority (CASA), the European Aviation Safety Agency (EASA), and others.