uni-ball Impact RT Retractable Gel Pens, 4 Black Ink Pens(66901PP)

Pen's hefty size allows great control as it produces a thick, vibrant line
Innovative auto-retractable tip withdraws into the barrel as you clip the pen to any surface
Acid-free for documenting and record keeping
Waterproof ink to protect against spills Uniball’s standard gel refills are smoother than most others, and the “bold” version is even smoother. A larger ball rolls over rough paper just as larger tires are better for rolling over rough terrain. More »