Our outdoor heaters are virtually indestructible, made from cast iron it is cast in a unique way, in one solid piece, there are no moving parts, no air vents are required, no grates either, due to its clever design it draws perfectly giving a very efficient clean burn and as such has very little smoke and minimal ash. You will only need to clean out the ash approx every 3-5 yrs. All the ash burns away to nothing on the bed of sand leaving no mess and no hassle, no maintenance! Ideal as an outdoor fireplaces/patio heater.