Compact and portable energy light produces blue light like a clear summer sky. This particular light therapy is known to naturally help increase your energy level, alertness and help fight winter blues in a natural way. Specific blue light, light intensity dimmer (4 levels) , advanced diffusion optics, wide treatment field, easy to use and compact to fit easily in purse or bag. Runs 4 hours on charge if wall electricity not available, set clock to turn on/off to wake up to light, excellent condition.