Pinner says - These pens are pilot frixion gel pens. You can erase them. And they don't leave erase dust behind, plus they erase away completely. They come in markers, pens, and highlighters. You have to use special erasers but they are amazing!
For The Girl Who Loves Color Coordinating Everything - Poppin Signature Pens Mistakes Happen These Pens Let You Hide The Evidence - Pilot FriXion Color-Pencil-Like Erasable Gel Ink Pen - mm // Pilot FriXion