Making a tactical pen into a more useful multi-purpose tool.

I'm thinking a good tactical pen is good in emergency. Thus, a survival kit. You could research this by going camping for a night with no equipment. 

1. A fire lighter

Good against cold, used for cooking, protects against animals, provides light. 

2. Water filter

We are pretty much used to tap water. Want to drink from a muddy pond? Use a filter. 

3. String?

A good string is pretty useful. 

4. Access to the internet

Guessing this would be the first thing most people would miss.