This is one my favorite nibs. It's stiff but not too stiff and has a little flex to it (not as much as the Tachikawa G which will be reviewed in my next post).
You can still make beautiful marks with little pressure but also with more pressure, get more exaggerated thick & thin lines. I find that the hairlnes I make with this nib are finer than with the Nikko G and the downstrokes are not as thick as those made with the Nikko G. But the differences between the two nibs are very slight and could just be in my mind.
I am using a pronged style of nib holder with this nib but the Zebra G can also fit on the Speedball B holder (standard black plastic holder).
Since I have a bunch of calligraphy nibs on different holders, the way I can tell if the nib is a Zebra G from a Nikko G (without having to pull it off), is in the tines area (that is the area above the point/tip of the nib), the Nikko G has a pattern on that area, very thin horizontal lines, when you scratch your fingernail over that area, you can feel it. The Zebra G is smooth in that area.
I haven't found a store in Portland, Oregon that carries this nib, but they can be found at Jet Pens for a pack of 10 for $13.50; at Paper & Ink Arts for $1.95 each (pack of 10 is $18.50); or Amazon for $9.99 for a pack of 10.