So when I ordered that Sdkfz 222 I got myself this Agama thinner as well. I think I read something about it on Armorama and thats why I got myself a bottle to replenish my almost empty bottle of Vallejo Thinner.
I have absolutely no idea what it contains. But it does wonders with the airbrush. Firstly it's transparent, so you can mix in the cup and directly see what colour you will be spraying. It also extends the colour and acts as a thinner. So if I want to spray really transparent layers I add a mix of 1:5 ratio paint to thinner. With the Vallejo & Liquitex thinners they usually extended the colour much much more, making transparent layers tricky.
Mixing a 1:1 ratio just makes the Vallejo Air much thinner but keeps the color more or less as opaque as it is straight from the bottle. My Model Air colors might be a bit old since they feel a bit thick, and I usually dont want to dial up the PSI to 30 just to be able to paint without sputtering.
It also seems to contain some sort of slow dri additive since the acrylics dont clog up as much as they did with the other thinners I've used (apart from the window cleaner). But it still evaporates quick enough to not create runs if you paint on too much.
So... highly recommended product. Especially if you live in the EU.
The only downside is the packaging. There is no spout on the bottle, so I have to use a pipette. I guess I'm spoiled by Reaper/Vallejo and their dropper bottles. :) It might be that the smaller bottles come with a spout on them.
I got mine from Jadar Hobby. A polish retailer. They send the stuff pretty quick. Or at least quicker than what we're used to when ordering stuff from our Friendly Online Gaming Stores.
Thats it. Back to chipping and stuff on the SdKfz 222!