Power by light: it does not get more effortless than this. This keyboard charges itself whenever there is light and stays charged for at least three months in total darkness. So you can say goodbye.Comfortable typing experience: It combines the best of a traditional keyboard, laptop, and concave keycap design.Slim, light, and powerful: Meet the slim, full-sized keyboard powered by light.Easy and quick Logitech unifying connection: Connectable via unifying USB, the receiver can remain on the laptop without frequent plugging and unplugging. 2.4GHz wireless connection, stable and not dropped.