If you want to be able to just unscrew to refill without removing a valve, this is for you. That's it. That's all it does. Is it it worth it? In my opinion hell yes.
I started using Molotov 127's to do highlights on my illustrations. I liked that they are refillable and have interchangeable/replacable nibs. But my very first time doing a refill, I accidentally separated the valve and had the spring fly out and basically destroyed it.
Since then I've mastered removing that valve, but when I use these on my markers it's not even a concern. I don't have to find a spot to put the ink-covered valve down on. I don't even get ink on my hands. Yes the ink will wash off but constantly washing my hands leads to f*cking up my skin. So for my uses, these are great.
The Euro Fat Cap is good for flares and shows the dot in the center when first sprayed. The width I got was at 8" inches. That means this cap is good for throw - ups and outer out- lines. Probably misting and shading colors into a well made piece.
We use the smaller round nib version of these in the oil field to mark our filters,top of the line markers,will write over dripped sweat and thin layers of grease.you really can't go wrong with these,they just flow so nice.good markers with good paint,what more could you ask for from a marker,and these are oil-based so they will last for years out in the sun without fading.