Zebra Z-Grip Retractable Ballpoint Pen, Medium Point, 1.0mm, Black Ink, 7-Count

I have bought 4 packs of these pens. The ones that work, work well for a long time. First pack, all pens worked. Second pack, 2 pens didn't work. Thought it was a fluke, bought two more packs because I did like the way they write. Mistake. I've got 5 pens out of 14 that will not work. The ink just does not start to flow (after trying 1/2 dozen times) and the pen is worthless. That works out to about 25% that don't work. Not a huge amount of money lost, more annoying than anything else.