"The Only Propane Campfire That Feels Like A Real Fire" - Popular Mechanics What makes the R4 the worlds warmest propane fire pit? ✅ Proprietary A-Flame Burner After years of mathematical modeling and experimentation, this is the brightest, cleanest, most weather-resistant flame ever created. ✅ Patented BARCOAL® Tech BarCoal is the world’s first radiant tube heater that's naturally aspirated and works entirely off-grid. With a peak temp of 1,200 ºF and 100% primary air combustion, the system is