"As with any weapon or fighting technique, you can’t just go throwing one into your bug out bag and then call it a day. You will need basic training at the very least. A baton is well worth the time you spend training with one, due to its portability, packability, and the element of surprise.
The ASP Agent Infinity is the smallest we recommend and was the EDC pick in our baton review: Best Expandable Baton for Self-Defense."