The Surface Book pen has these functions:
1 - Click the eraser button to take a screen shot via OneNote
2 - Write with the pen nub. Pressure sensitivity greatly improved over Surface Pro 3 pen
3 - Erase by turning the pen around and touching the eraser on the screen. No button pressing necessary.
4 - Hold the eraser button for more than 1 second to open Cortana's search window, rather than speaking, "Hey Cortana". Better in public places.
1 - Click the eraser button to take a screen shot via OneNote
2 - Write with the pen nub. Pressure sensitivity greatly improved over Surface Pro 3 pen
3 - Erase by turning the pen around and touching the eraser on the screen. No button pressing necessary.
4 - Hold the eraser button for more than 1 second to open Cortana's search window, rather than speaking, "Hey Cortana". Better in public places.