The duct coupler works with just about all flexible ventilation hose from Euramco. This includes the Ecko and RamFan lines of confined space ventilation blowers. The idea is simple; any duct that has the adjusting/tightening belt can be adapted to the coupler. This allows you to extend the duct length, adding one piece to another. Pick the duct coupler size that corresponds with whatever size duct that you have or are ordering.
DC12 12 in. diameter stainless
DC16 16 in. diameter stainless