W&P # 1121 This unique pen has a small green LED tucked into its tip right next to a high quality medium ball point. Just give the top of the pen a twist, and you can see what you are entering in the log on those long dark nights without having to light up the whole cabin. This Translucent Blue pen comes with a clear cap to help prevent leaving it turned on accidentally. Also allows you to clip it to your chart or pocket if you just need a small light to see by. Runs for hours on end using 2 LR44 1.5 volt batteries (included) located in the top. Wt. 7 oz.