Ah I ran into the same thing initially.
The term PID stands for Proportional, Integral and Derivative.
Those terms are the control configuration parameters.
A very very very rudimentary explanation is that you set the Proportional value to really drive the control.
The Integral value to assist in holding temperature in range, and the Derivative value to assist with temp adjustment taking into consideration the change in temp over time. (Ya I know this isn't the 100% most technically accurate explanation but it is an intro explanation.)
When you plug in values and tune all 3 values into the controller, they work together you get very tight temperature control.
Auber makes some good ones at good prices for the average joe who doesn't have the tools, setup, or a deep enough knowledge to start assembling their own.
Here you can see some good and simple Plug and Play (after a simple MES rewire) PID Controllers from Auber:
https://www.auberins.com/index.php?main_page=index&cPath=14_28&page=1&sort=4d
If you start with the model: WS-1510ELPM and move upwards towards the top of the page (and in price) you should see all models that will support the 1200 Watt MES.
The MES is physically built quite well. It's weakest areas are the controller and some poor/cost cutting decisions to use sub-par electrical connectors on the heating element and safety rollout limit switch.
If you correct the limitations/weak areas and add an AMNPS then you have as good of an electric smoker as you can sensibly buy!
Let me know if all of this makes any sense. Also, feel free to ask away about any questions you may have :)
