Suppression of global warming is a global issue and countermeasures are being taken for products in various fields. Transport refrigeration units installed in many trucks and trailers that support the controlled temperature transportation infrastructure for perishable foodstuffs, pharmaceuticals and industrial raw materials are also required to play their own roles, while reducing the impact of global warming at the same time.Mitsubishi Heavy Industries Thermal Systems, Ltd. promptly developed the TU series, engine-driven transport refrigeration units (hereinafter referred to as the "developed product") that use a refrigerant with a low global warming potential (GWP) in order to lead the contribution to the suppression of global warming in the transport refrigeration unit industry. This report presents the developed product.