The problem with normal highlighters is twofold: even the best ones can blur ink on printed out documents (not as much books because the inking is of better quality; this is mainly an issue with articles or papers that you print out on a home printer), and secondly, you cannot erase the highlighting.

These pens are great for highlighting important information and then being able to erase when things change.

quite perfect for the work i do if i make a mistake and hightight the wrong thing i can erase the highlight

Wait a second or two for the ink to dry before trying to erase, and be wary of the integrity of the ink you're highlighting over (rubbing out an accidental highlight might smear the print underneath it).

The BAZIC ones have like a magic ink based erasing mechanism while these are more friction based in that you actually erase the highlighting like you would erase pencil markings

The highlight is so dark you have a hard time seeing the text.

I was pretty skeptical about the actual ability to erase the highlights but was happy with how well they actually do erase.

The erased highlights do show up again after being put in the freezer and they look just as bright as they did originally.