The U2 SMART ONE offers all the same benefits as the U2 SMART but with one inch printing. The other difference is that it only takes one ink cartridge, the SP4-1 cartridge, 42ml. This printer is the most cost-effective solution with exclusive ink selections for porous & semi-porous printing applications. The ink cartridge eliminates unnecessary printhead services. It is truly zero-maintenance and drastically decreases cost of ownership.