I have the 9,000 BTU and 18,000 BTU models and love them. They have low oxygen safety and tip over safety (not sure about the small one in the picture). Two tips if you are using it in a cloth type ground blind when brutally cols put it behind you and cover up with a blanket the heat will radiate up through the chair and be trapped. Second bring a long nose lighter (keep it warm so it will light) as the igniters are the loud snap type. In a enclosed blind you will have condensation on the windows as water is a byproduct of combustion so remember you will have to deal with that. They should be vented a little to help rid the excess water and a some ventilation.