This document provides technical specifications for the ECKA 51/51/51R wood burning stove. It lists nominal heat power, efficiency, wood consumption, flue gas measurements, heat distribution capabilities, required chimney pressure and air flow, dimensions and weights. Specifications are provided for operation connected directly to chimney, with a cupola, adaptor, hot air exchanger, and vertical hot air exchanger. Additional components like build-on frames and cover frames are also detailed.