Product review (5 stars): Along with a good vent cleaning, this fixed my NGD7200TW gas dryer!
My Amana NGD7200TW aka Samsung gas dryer quit drying the clothes. Actually, it still dried them but took forever. The flames came on, but went out quickly - like a minute or less. I could tell this by watching the gas meter run. It used to dry quickly and completely, so something was certainly wrong. First I tried replacing the gas coils. Nope. Then the cycling thermostat, the one on the burner housing. Nada. At this point I did what I didn't want to admit needed doing - clean the entire vent from the dryer to the outside. I stuck vacuum hoses in from each end. I blew it out with an electric leaf blower. Still, the clothes didn't dry. So I took apart the blower housing, took off the blower wheel and cleaned the entire dryer cabinet. Clothes still don't dry!

I read about some other guy using a leaf blower and how that had been unsuccessful. So I got an actual dryer vent brush with a 10 foot cable and forced the cable in from one end, grabbed it and pulled it all the way through. A gigantic clog of lint came out that was easily large enough to plug the vent. Then I dragged a rag through and blew it out again with the blower. Finally, my vent was clean. CLOTHES STILL DON'T DRY!

So I bought one of these little dudes, and it fixed it. The burner stays on a good long time and the clothes are dry using the sensor dry setting again in a reasonable time. I feel like running the dryer with the clogged vent killed the old one. My old one measured 12K at room temp, and the new one was more like 10K. It was apparently shutting down the burner prematurely. Moral of the story - clean your vent the right way every few years; and your dryer cabinet too. This was a good way to get familiar with my dryer, which is probably good because I expect the belt to break any day now.