Only use these, buy at local crafts store. Number 2 is most used, number 1 like Citadel Small Layer. It's about 100-200 rubles per brush (2-3$) and they beat Citadel any day. Hand made and dude who owns the brand is quite a fan of making good product I heard.
They come in packaging and with a plastic top.
http://static.diary.ru/userdir/1/1/6/0/11604/86299559.jpg
http://static.diary.ru/userdir/1/1/6/0/11604/86299560.jpg
Depending on the series there are long handles, short handles, shorter bristles or longer ones. Also the hair can be stiffer or softer (softer hair takes paint easier). I feel like 1110 and 1112 is softer, 1115 is more rigid.
Number 1 is already so fine I don't buy 0 or 00.
http://static.diary.ru/userdir/1/1/6/0/11604/86299566.jpg
Thing is though, brushes come in all shapes and sizes and not always are perfect, although you can remove a bad bristle with pincers if you really have to. Which is why I prefer not to buy brushes online. Craft stores have shelves upon shelves of good stuff, and it's nice to pick out the best ones.
So yeah, if you can order some, for their price they are quite the performers.