They are freely available elsewhere, but usually at a much higher price
May not be the best, but what would one expect at that price.
All I can say is that it does it's job well. Covers the page with a bright even light, even at the one LED setting. 3 AAA batteries give a long battery life. I've been using mine for a few hours nearly every night for over 3 months, and the lighting has only just started to get a little dimmer.