If you've ever taken a pen on the go, you know how different characteristics of the pen affect its portability. The shape, size, clip strength, etc. all determine whether or not the pen is still with you by the end of the day. The Tombow OnBook addresses exactly that issue with its handy-dandy (and don't forget friendly) ballpoint pen. The pen features a strong, thin metal
clip that fits into narrow spaces such as notebook bindings, and the pen protrudes a mere 2 mm above the clip so that it won't snag or hit things. The slightly triangular body stays flush against your notebook or book without rolling.
To change refills:
To change the refill, remove the pen tip by unscrewing it. Then, pull out the old refill and insert the new refill. Screw the pen tip back on. If the tip does not fit properly, it may be because the refill was not pushed in all the way.