Rain entry into dead chimneys is one of the main causes of structural decay to chimney stacks. Saturated by rain entry they never dry out in winter where there is no fire. The freeze/thaw cycle causes a steady degradation of the mortar and masonry at great ultimate expense. The Brewer chimney capper is a simple value-for-money answer that prevents rain, bird and debris entry while still allowing nominal ventilation, essential in dead chimneys. Instant simple fitting to 13" x 13" square chimneys using the stainless steel strap. Please note the chimney is not supplied. Please note this item is buff painted.