It’s refillable through the screw cap at the bottom

The markers use a direct liquid ink system that keeps the line steady at a bold 2

useful for fading a stroke from dark to light

and fade-resistant

The clear flexible barrel holds 20ml of water

leuchtturm1917 notebook master a4 slim squared Skolestart It’s refillable through the screwA precise 5 x 5 mm graph grid notebook in a matte black oversize hardcover the A4+ format at 225 x 315 mm gives software developers, engineers, and technical draftsmen significantly more graphing space than standard A4 for charts, calculations, and architectural wireframes. Standard A4 prints store flat inside without edge damage. 100 g m ink proof acid free paper, thread bound flat lay hardcover, 121 numbered pages. Format: A4+ (225 x 315 mm) 121