I use it to preheat the bottom of the SMT boards while blowing hot air on top. Works well. The temperature seems stable and everything is of acceptable quality. I'm not exactly sure what the temperature shown on the display refers to, but relatively speaking it's very constant and you can run the process. I build boards on a table using a template. and tweezers. Basically 0805 are the smallest I need. Then I move the boards into this heater one at a time and cap them with hot air.