Bird Screened Chimney Cowl| Bscowl Stainless Steel Corrosion proof Easy fit Prevents bird entry Reduces rain ingress Size: 8" Bird Screened Chimney Cowl For 8" Flue - Stainless Steel | Bscowl Designed to fit and adjust on a conventional clay chimney pot with an 8" (200mm) internal diameter. (9" (230mm) ext. diameter). The Clean Sweep Rain & Bird Screen Chimney Cowl will prevent birds, vermin and rain from entering your chimney flue. It is made of robust stainless steel in an attractive design. It features a universal toggle fixing that will suit any chimney type.