The video shows an embossed interpoint braille book, which is hard for sighted teachers and assistants to read visually. A dirty/well used Expo dry erase eraser is used to highlight the braille, making it easier to read using vision.
"Interpoint braille" means that the book has braille on both sides of the page. This takes up less space and is not difficult for tactile braille readers, but it can be tricky for someone who reads braille visually.
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