Regency's Greenfire Medium Pellet Insert includes an adjustable hopper, allowing this unit to fit into fireplace openings as low as 19.5". Steel fluted liner panels compliment the large bay ceramic window and gives you an exceptional view of the fire. The heavy-duty heat exchanger will burn pellets completely and any remaining ash will fall into the concealed ash pan (included). This unit gives you the most out of your fuel and the extra time to do the things you love.