ThermoFlo™ Connectors make it simple to connect two segments of round duct together where added stability and sealing is required, such as passing ventilation through a wall. Ducts are easily coupled by sliding each piece over the connector end up to the ridge (provided as a guide). Specifically designed to be used with ThermoFlo flexible ducting, these connectors are crafted with powder-coated heavy-duty galvanized steel to the highest quality standard.