Levenger 6 Levenger Medium Fiber Tip Refills - Black Writing tip is spring loaded (with a polyester ink reservoir) to adjust to your writing pressure-a nice feature. Fits any of our True Writer Rollerball Pens. Ink dries quickly, which is very helpful for left-handed writers. Extra Fine is. 8mm, write out is 2624 feet. Broad is 2mm, write out is 1968 feet.