Uni-ball R: E is a smooth-writing gel pen whose ink becomes transparent with heat. To erase, use the plastic eraser under the button, which will not stain or wear. The smart mechanism locks the button for deletion so you can delete it conveniently.
P.S Do not use an erasable gel pen for important writing that requires a long time. Also, do not leave your writings in a hot car or in the sun. In an emergency, the expended ink can be exposed to some extent by placing the paper in the freezer for a while.