I am an amateur and I use the 2mm very often and the 2.5mm rarely (depending on the type and nature of the work). I always buy the packaged 2.0mm boxes of 3.5 Kg, so they are always sealed, and I don't order random weights because then they come... loose. These particular Greek-made Fincord-M electrodes from ERLIKON are, as always, very good, maybe among the best on the market, with the best quality, and perfect in burning and welding, from any welding position. Easy ignition and comfortable welding at low Amps without 'straining' the welding machine, as has happened to me with other imported electrodes that made things difficult for both me and the machine because they needed more Amps... So with these, apart from the ease of use, there is also an improvement in the Duty Cycle rate of the machine. You can easily use them with any welding machine, IGBT, Inverter, Moving Core, or Fixed Transformer, even with the cheapest Chinese ones on the market. Personally, for the past 4 years, I have had the cheapest Chinese one on the European market at 45 euros, the 'StanWerk MMA-250', which is the corresponding Chinese ZX7-200, which is also portable, and the same device is still available, carbon copy, in various other brands but now a bit improved from the older version I have. This device, together with the use of these specific 2.0mm Fincord-M electrodes from ERLIKON, has served me well in many small and larger jobs. Of course, like all electrodes, they need a lot of care in storage to avoid moisture. The only downside of these is the packaging... the cardboard of the box is very thin and tears and gets damaged easily during transport and handling. I have the impression that a long time ago they had much thicker packaging cardboard and much thicker nylon so you could keep them in their own box... Now I have to put them in my own airtight plastic box.