Yep, it's a colloidal silver generator. I would never use it though, you can't make good colloidal silver with that contraption. You need to use a constant current power source with an accurate mA ammeter to be able to know the actual ppm you have when finished without expensive testing or educated guessing based solely on final liquid color. You also need everything to be done a certain way in order to make particles within a 10-20nm size range, which can't be done with a simple unit like that. Larger particles do almost nothing for the body, and smaller particles can start to damage healthy cells. 10-20nm sized particles have been shown in peer reviewed studies to have noticeable benefits for killing viruses and bacteria at overall concentrations between 5 and 20ppm. There are many medical studies proving that, some showing the effectiveness of ingested colloidal silver, others showing the effectiveness of nebulized colloidal silver. Silver does work quite well if used correctly, that's why bandages for burns often now contain silver to help speed up healing and reduce infection. Over 20ppm concentrations can also start to kill some healthy cells, just as particles that are too small can. There is a lot to it, you can't just put a couple batteries together and stick a couple silver rods into water and make it if you want stuff that actually benefits the body.
Skin turning blue is the result of many bad decisons being made over a long period of time by someone that had no idea what they were doing. The skin turns blue from ingesting high levels of silver chloride. Silver chloride is what your body ends up with if you make or injest Silver Chloride directly or if you injest clear ionic silver, which is what many sellers of colloidal silver are actually selling. Ionic silver reacts with the hydrochloric acid in the stomach to create silver chloride when ingested. Turning blue is also a progressive thing, it doesn't just happen overnight. If you were sane, wouldn't you stop taking silver after the skin under your fingernails started to turn blue instead of waiting until your entire body turned deep blue and you ended up on Oprah? Anything is deadly or can cause complications if you are an idiot. You can die from drinking too much water, but that doesn't mean water is bad.
True colloidal silver is a light yellow color at low concentrations and it will not turn into silver chloride when ingested. It should also have no taste. If it tastes metallic and is clear you are drinking ionic silver. If it tastes metallic and it's a light yellow color, that usually means the colloidal silver wasn't fully reduced when making it, so there's some ionic silver left in with the colloidal silver.
Contrary to what most websites will tell you, Argyria (body turning blue) is reversible over time even if it does happen to you. I can't remember off hand what the main supplement used to help it to go away over time is, it might be high dose selenium. There are studies and test cases proving the issue can be resolved, I have read them and seen before and after pictures of the results. You don't really have to worry about that though, you will never create the scenario that would cause argyria in the first place if you only take actual colloidal silver in concentrations and amounts that are beneficial for the body. Silver isn't supposed to be a supplement you take every day, but if you make the correct stuff and use it correctly it can work wonders to help someone heal from a cold, virus, or other lung infection quickly. It has even been shown to be very effective against covid, especially when nebulized. There's no money in it though, that's why most have never heard about it.