I'm an aircraft owner and use this very powerful LED-powered pen during night flying, but also while traveling on commercial flights and mostly at odd times: crosswords, fishing for something in the car at night, etc. The lighting and ink are independently controlled, so in addition to being effective, it's easy to use: the button on top is on/off for the light and the pen rotates to retract the ink. I've had some promotional-type LED pens in the past, but the button cells burn out and then it's difficult to replace them. This pen runs on a single AAA cell, which is easy to find and replace. The pen also comes with an extra battery and ink cartridge for $20 (with shipping) -- not too bad.