This document provides technical specifications for the ECKA 51/51/51L wood burning stove. It lists details such as nominal heat power, efficiency, wood consumption, flue gas temperatures and mass flow, required chimney pressure, combustion air requirements, and dimensions. It also provides information on using the stove connected directly to a chimney, with a cupola, hot air exchanger, or adaptor, as well as connected to an accumulation mass. Installation options including a build-on frame and cover frame are also specified.