Harvia Full Protective Sheath For M Series Sauna StovesThe Harvia WL450 protective sheath is designed and approved for wood heated Harvia wood burning heaters (Harvia M1, M2, M3 and M3 SL). The protective sheath considerably reduces the safety distance to combustible materials in practice, this makes the wood burning heater fit in a smaller space. The protective sheath is attached to the wood burning heater and conforms to the shape of the wood burning heater, making the combination sleek. As the Harvia