These things are dope as hell, perfect for bringing to court, the airport, a funeral, or anywhere you know you won't be smashing tuff, but still want the option. Hell, I might even keep one hooped for the next time I get locked up - they are that small. A single fill goes a lot farther than you would expect.
As for the nib being tight as hell, if you finesse the insertion/removal you should be all right. But since my homies are lazy, I tried out running a dremel with a sandpaper attachment in the opening of the body. This eases it up a bit, but still keeps a solid seal. Haven't had any problems so far so I think I am going to do this to the rest of em.
Bought a 20 pack to fill with my home brew paint/ink (it works great with both) and give out to the homies in the crew for antichristmas. When you buy 20 you get them for less than a dollar!
These dope little nibs also work on the Grog squeezer 05 and the Kobra nano mop, they also fit perfectly into a bunch of random things. Those zig zag vape liquid refills work great for a easily made mini mop. You gotta drill out the cap so the nib fits or find another cap, but that is easy enough.