I don't know whether a word "erasable ball-point pen" makes a sense to English-speaking friends. This ball-point pen is very unique in a way that you can erase without ink eradicators or erasers. Ink disappears simply by rubbing, using a hard rubber attached to the other end of a pen. The manufacturer developed this special ink of which color is just rubbed off by way of friction. Isn't it something? Heat does count. This special ink supposedly loses its color over a heat of 60 degree Celsius. Then even a hair dryer can be an instant eraser for this ball-point pen. I use it for my schedule book I carry with me in my bag everyday. It's so useful when my schedule needs to be rewritten then I don't have to make a mess any more in a small space with lot of strike-through.
But there is one thing that you've got to be careful using this pen. Don't use it in writing an address on an envelope or a postcard. An automatic postal code reading machine might erase your friend's address on a post card with its own heat on the process. Mr. postman will be at a loss.
Look here. It's fun.