Pilot Jumbo Permanent markers have large chiselled nibs, and are filled with ultra permanent Pilot brand ink | One really nice feature about these is that they are easily refillable with Pilot Ink and the nibs are built so well that these markers last | The 10mm nib is built tough and can write on more surfaces than most markers | Pilot Jumbo markers also have a large ink capacity so you don't have to refill them as often | The Pilot SCA-6600 Super Colour Jumbo Permanent Marker is perfect for big and tough marking jobs | Supersized industrial marker has a chisel nib, giving it a 3.0 mm nib at its finest and 12.5 mm nib at its thickest