I have an Englander NC13 mounted in my fireplace as an insert. With the blower mounted in back, I had no way to control the blower. I had one of the HF router speed controllers sitting around, so decided to try that out. Left the blower on hi & use the HF unit to control the speed Works great! Where it also comes in real handy is changing the speed away from the resonant frequency speeds that the blower hits when the blades get dirty. This is my third season with it & I thought I would pass the tip along. Al http://www.harborfreight.com/router-speed-control-43060.html P.S. I only paid $12 for it on sale.