No one made a plug in USB keyboard lamp with red light so when I spotted this one I thought it was worth a try. It gives the right amount of red light to keep dark adapted but if I have a (s;light) criticism its that the light is not spread out enough for a typical laptop keyboard. When the night vision in Stellarium is turned on it helps and lowering the lamp so it shines across rather than down improves the illumination across the keyboard.
Not bad for the money