Ensso Pen Uno

From Los Angeles design studio Ensso, the Pen Uno is a study in functional simplicity. It’s precision-machined from aluminum, with a sliding barrel that serves as both a wide grip section and a cap that protects the tip (and your pocket) while in transit. Twist the barrel to the left to move it down the length of the pen when you’re ready to write, and then back to the right to move it up over the tip. At just 5.3 millimeters in diameter, this is one of the slimmest pens on the market. Plus, it’s easy to maintain: When it’s time for a refill, use a flathead screwdriver (or even your nail) to remove the end cap and access the ink cartridge inside.