Many companies today require a spark arrestor to be installed on any solid fuel burning device. Such as, a pellet stove, corn stove or any type of wood burning device. Such as an outdoor wood burner, a free standing wood burner in a home or outbuilding, an ad on wood burning furnace attached to your LP or Natural gas furnace.
The reason they are asking for this type of device to be added is to prevent a fire from a floating spark or ember out of the pipe or chimney. It just takes one floating ember to land on a dry leaf or grass or any type of wood or flammable item in its path to start a major fire and destroy your property.
So it is for your protection that this device is asked to be added for your safety as well as all others in the area of the solid fuel burning device.