Uni-Ball AIR - 0.7mm Medium Rollerball - 6 Pack - Blue - UBA-188-L

The revolutionary nib of the Air unlike conventional rollerballs is pressure sensitive meaning that it gives a writing experience and differentiating line width similar to that of a fountain pen. The metal ball of the nib is encased in an acetal plastic rather than the standard metal surround which allows for a smoother flow of ink around the ball and an increased flow as further pressure is applied. The 0.7mm ball delivers a line width of between 0.35mm and 0.55mm (dependent on pressure).