2,5mm Steel frame. 4mm perimetrically plated combustion chamber. 25mm Vermiculite (SF750) base. Features 25mm perimetrical rockwool proofing and 25mm ceramic-wool top proofing. Ash container (drawer) placed at the bottom.  Ability to connect with hydrostatic valve (not included). Ability to convert to a pellet boiler using the TORO 40.