Calligraphic nib arabic stroke 2.4 mm. The Arabic calligraphy nibs are Naskhì, Nasta'lìq, Tuluth. Mounted in a black plastic tip, they can be removed by pulling lightly and separating the power supply from the nib. For a thorough cleaning it is necessary to leave them immersed in a container with lukewarm water. Plastic nib and Iridium tip material.