In-Line Spark Arrestor / Stack RobberThe In line Spark Box is designed to have a spark arrestor just above the stove. 5" version is the black model seen in the pictures. 4" & 6" versions are silver model seen in last picture. These are a special order item and may take up to 6 weeks to ship. Prevents almost all ash and sparks from going up a stove pipe and onto wall tent roof. You can clean your inline spark arrestor daily without having to take down all of your stove pipe to clean the