The document provides technical specifications for the ECKA 51/51/51h wood burning stove. It lists nominal heat power, efficiency, wood consumption, flue gas measurements, heat distribution percentages, required chimney pressure, combustion air requirements, and dimensions for the stove when operated directly connected to a chimney, with a cupola, with an adaptor, with a hot air exchanger, and with accumulation masses. Frame sizes and dimensions are also specified for building-on and cover frames.