Nekigoen Parker Compatible Rollerball Pen Refills Work for Most Brands Pens with Smooth Writing, Waterman Compatible Rollerball Pen Refills Standard Size Pens Fine Point 0.7mm Pack of 15 (Blue Ink)

Many years ago i was gifted a pen by my wife that I have kept as a memorabilia. I had a hard time finding a insert for it. This one fits perfectly.

I was given a lovely Case xx (knife company) pen. When I needed to replace the ink, the brand on the ink waz Zappo. Amazon does sell Zappo ink, but it was more than I wanted to spend for only two cartridges. After measuring the cartridge, I ordered these and it's perfect! The ink is just as pretty and smooth as the original ink only a beautiful blue instead of black. I'm thrilled! This is now my favorite pen and ink.

This is pretty good product for the price and given the giant "Made in China" sticker on the package. A bit darker blue than I expected, but a perfect fit (non-branded pens...I just measured the length of the old refill and shopped for something that fit). A pretty fine point, smooth writing, revived some old pens whose grip and feel I liked but whose ink had run dry.

These did not fit any of my three Parker Rollerball pens. To work I had to add a spring to the back of the pen barrel and then the point was wobbly in the screw-on sleeve and sticks out way more than a standard refill. Not sure why they say it works with Parker. It does not. DO NOT purchase for Parker. Sending mine back.

The refills fit into 6 pens I already have 3 of which were running low on ink. I used 3 of these to replace the ones that were low. Of the three of these refills I tried only one worked (sort of) as claimed by the seller. The two that completely failed to operate correctly didn't "write smoothly" as claimed on the box and one actually tore the paper upon which I was trying to write. As for the other claims on the box, I can well believe that they do not "leak" or "smear" and have a "long lifespan" if you measure that span in terms of ink consumption. This is because almost no ink comes out of the (fine) point. If you measure the lifespan by the number of days before you get angry and throw them in the trash or run over them repeatedly with your truck, then that lifespan may be short indeed.