1. Economy: by use of 1pc AAA, change and buy easily; while old LED light pen is only by use of button cells (difficult to buy and expensive, some leakage problem)2. Long time use: the capacity of AAA is 10 times higher than button cells, price is less than 1/63. Extra light: by use of 2 extra white LEDs on the tip of pen for practice lighting; while old LED pen is only by use of color LED and in the middle of pen which can not be used for lighting, just decorating4. Environment protect: both battery and ball pen core can be changed, also these two elements can be bought anywhere in the world; while some old LED light pen is disposal and one-time use5. Easy to be carrying: light as normal pen with clip, can put into pocket with easy6. Convenient: can be used as normal pen in daytime (light off) and as lighting pen at night (light on)7. Low use cost: both AAA battery and pen core are cheap, and almost all the pen core can be adapted to be used in our LED light penBesides we are developing many LED light pen, just change the white LED into UV, we can produce UV money detector pen; just change the ball pen core into stylus which is used for handwriting of PDA or mobile, we can produce LED light stylus pen.Packing:Transparent PVC, double blister, display box producing area:China payment:T/T supplying capacity:50,000pcs/month