The machine is great for hobby grade use.I would not recommend for professional use.The pens get very hot after about a half hour continuous use that I have to turn off and coll down or switch to the other pen.
Some of the tips bend out of shape alot due to the heat produced.
Carbon build up happens no matter what you do a piece of sand paper is useful to have near by.
The price was reasonable for some reason these tools are hard to purchase In Ireland so had no choice but order on line.
Over all a good unit to build skills and see how you go with the hobby.