The build quality is good for the stated amount, however the device can't keep the temperature below 80-90 C. The first 30% of the heater potentiometer stroke literally doesn't give any heat, but the heater light is on. After the potentiometer is turned up more than 30%, I get a minimum temperature of 80-90 C. For this reason, it is impossible to set the temperature to a lower value and maintain it there, because the device can't do that. You literally have to turn the device on/off for a temperature lower than 80-90 C, which means the device is not working.