Builder’s Best is a nationwide, high-performance manufacturer of quality venting solutions, designed to meet specific constraints of areas such as dryer venting, bathroom fan venting, fresh-air ventilation and general venting. The Black Metal Roof Vent Cap (6 in. to 8 in. (3-1/4 in. x 10 in.) Universal Flush) has an electrically bonded epoxy finish for durability. It even has a back-draft flapper.