From their website:
In 1977 a small custom sheet metal shop, known as Spring Branch Sheet Metal (SBSM), opened its doors with seven employees. After years of producing sheet metal products ranging from roof gutters to kitchen hoods, SBSM found a niche in the market of HVAC accessories. In 1983, the name Curbco was trademarked and the evolution began from local sheet metal shop to a nationally recognized supplier throughout the HVAC industry.
Today Curbco enjoys national recognition as a leading supplier of curb adapters, package equipment curbs, fan roof curbs, equipment supports, and metal building curbs for every major manufacturer in the HVAC industry. You couldn’t be in better hands if you need a precision-made solution for your rooftop curb needs. Go with one of the original grand masters in curb adapter design and engineering — go Curbco!