Levenger 2 Extra Fine 8mm Fiber Tip Refills, Blue (PR1145 BL EF) Writing tip is spring loaded (with a polyester ink reservoir) to adjust to your writing pressure - a nice feature Interchangeable with most rollerball refills (it fits the Levenger True Writer Rollerball perfectly) Ink dries quickly, which is very helpful for left-handed writers Write-out is .31 miles or 1,640 ft. +/- 30% Tube is nickel-plated brass, the front section is plastic with a stainless steel tube End plug and cap are in the color of the ink refill