Kuretake Zig Letter Pen CocoIro Pen Refill - Super Fine - Royal Blue

Nice color; it's usable for work. However, to get any variation in stroke width, you have to press down pretty hard and even then, it's not much of a difference. Pretty disappointed in that aspect. However, it is a good extra fine felt tip pen. You could just use the refill by itself, because it includes a cap.