Yesterday I got a similar one from my local Lidl store
Mine has a little drawer for storing the extra tip and solder rolls, but otherwise it seems identical.
I did a quick teardown and it is triac controlled, just like light bulb dimmers.
The board is nicely designed and manufactured though, with a small common mode choke and X and Y caps for line filtering, properly crimped earth wires, etc.
The tip is directly connected to earth (zero ohms resistance)
What I didn't like:
-The handpiece is HUGE. Trying to do precision soldering with that thing will be tricky
-The handpiece cord is very thick and stiff, identical to the power cord, which up to a point is to be expected, since there's mains voltage in there. They should use a thinner cable there, I guess they are more expensive and this is built down to the penny.
-The base is too light and can be tipped over very easily. The thick and stiff handpiece cord doesn't help either.
-The tips are plain stainless steel and do not wet with solder well.
-The tips have very little thermal mass. Wiping the tip on the wet sponge will cool it down enough to solidify the remaining solder.