Tom's Studio Lumos Pro Duo PenA Dual Ended Pen With Interchangeable Tips The Lumos Pro Duo Pen was designed as an answer to disposable pens. The Tom's Studio Lumos Pro Refillable Dual Tip Pen provides a more sustainable way to write, draw, and illustrate. Sleek in design, the pen has a fineliner on one end and a felt tip on the other. Both draw from interchangeable ink reservoirs that you can refill with your color of choice. The sets come with nine other artists tips to give you