Metalman is the first choice of heating and sheetmetal contractors in San Francisco. Need gutters, ducting, fittings and everything job metal requires, they have it. If by chance stock is non existent, they have 10 employees making custom metal fabrication Monday through Friday. Cutting edge with the newest and better choice furnaces and tankless hot water heaters. I was a contractor in SF for 45 years and had quick polite and knowledgable service at their shop for 33 years. Wait your turn at the busy counter on a stool. Charlie, Joan or their tall son will give fast advice and help you load. A treasure find for folks in SF. One criticism, their prices have risen some in the last couple of years.