Harvia WHP1000M - Sauna Wood Stove Chimney Extension, 1000mm, Black SteelDescription The joint mechanism and the supplementary parts are wound together while the smoke pipes are locked in place with grooves. These innovative attributes are how this Harvia 1000 mm black steel chimney extension prevents movement caused by temperature changes. The black powdered coated steel makes for a sleek addition inside or out. Features Innovative design Black powder coated steel Prevents movement caused by temperature changes Can be