1250 x 600mm Closure Plate with Brackets
If a chimney liner is being fitted, then a register plate is not required. A "closure plate" is required (to prevent heat being wasted by travelling up into the chimney and also to prevent "old soot smells" into the room as a chimney warms from the heat of the liner).
A closure plate is used when a chimney liner, containing flue gases, is present. The closure plate is therefore only required to seal the chimney for cosmetic reasons, to stop soot old soot falling on the stove but also to stop heat disappearing up the chimney and being wasted.
If a closure plate developed a fault (e.g. hole) smoke could NOT enter the room as the smoke is contained in a chimney liner.
A closure plate can be made of any non-combustible material.