Established in 2005, the M.A.D (metal anti downdraught) Cowls brand is a trading name of J D Burford Ltd. We stock their bird guard, which is designed to prevent birds, vermin and leaves entry to your chimney as well as their anti-downdraught cowl and capping cowl. Their anti-downdraught cowl has an aerodynamic shape that diverts directional wind across the top of the chimney drawing the smoke out while their capping cowl is used to cap off unused chimneys whilst also providing good ventilation.