A Chimney Cowl is a hood-shaped cover fitted to a chimney to increase ventilation and prevent draughts.
WIKIPEDIA ENTRY FOR COWL (CHIMNEY).
"I found ABIS in the Yellow Pages and when I phoned them they were very helpful with their explanations and answers to my questions. The girls, especially Maria and Lindsay, were very helpful as I had to change the appointment several times. They were very patient. My inspector was great. He was very thorough, explained everything, and again, was very patient. I am very pleased to recommend ABIS."