I bought this to use with my laptop, it has 5 a stage setting on the button. It is quite bright on the highest setting, but it is way too small for everyday comfort, it would be ok in an emergency situation, the problem being is that the length of the unit is way too short and it only just has enough length to bend over and stand up facing across the keyboard. If you're in the dark with no lighting, this will certainly help , I have no idea how fast it will drain your computers power supply, but a nice little emergency tool to keep in my laptop bag.
