Pilot Ink is ultra permanent Ink. It is famous for it's smooth flow and permanent formula. You can use this ink to refill the Pilot Jumbo Marker, the Pilot Broad Tip Marker, and the Pilot Fine Tip Marker. This ink can also be used in your favorite marker. Pilot Refill ink comes 30ml bottle with a pipette so you can quickly and easily refill your markers. A bottle of refill ink can fill a Pilot Jumbo about 10 times.