When you choose a Master propane convection heater, everyone within 5000 square feet with feel the warmth thanks to its efficient 360 deg heating radius. This powerful space heater delivers long lasting (up to 31 hours), electricity-free heat. It's like a bonfire without the open flame - perfect for barns, large warehouses, construction sites and loading docks. As you'd expect from Master, safety and convenience are built in to this durable product. Master built for power.