I have an older "Craft" brand fireplace insert model woodstove. I need a hose to connect an outlet on the side of the stove to a blower unit which will sit on the hearth. The outlet nipple seems to be about 3.75" outside diameter. What I *think* I'm looking for is a flexible metal duct type hose, black in color, 5 feet long would be plenty. I've looked online and can't find anything. Can someone tell me where to shop for this? Thanks Much!