Mechanical Pencils by uni. Details:Uni Jetstream inks are touted as enabling "smooth writing that becomes a habit." Smooth writing and sharp design come together in this multi pen that is targeted towards business professionals and designers. This pen combines four incredible 0.5 mm Jetstream inks and a 0.5 mm mechanical pencil in one pen body. The oil-based ink is water- and light-resistant and has an extremely low coefficient of friction. That means that the pen practically glides across the paper. Best of all, the specially-formulated ink has good flow, density, and color pigment, and it dries quickly.