Harvia WHP500M - Sauna Wood Stove Chimney Extension, 500mm, Black SteelThe Harvia Black Steel Chimney Extension (0. 5M 19 5 8) is designed to extend the height of your chimney system for improved draft and ventilation. Made from durable, insulated black steel, it safely handles high temperatures and supports efficient venting of smoke and gases from wood burning sauna stoves. This extension is designed for a secure fit with the Harvia WHP1500M Chimney Kit and helps maintain proper airflow for consistent stove performance.