Very useful, I firmly recommend the KeyDefender and have bought one for each of my family members.
Pros:
- It's reloadable.
- Functions very well as a supplemental flail/impact weapon when it runs dry.
- With training, it's a Kubaton/control weapon.
- Non-inflammatory training loads are available for practice.
Cons:
- Only two to four sprays per load.
- The nozzle can clog easily, if you don't PMCS it every so often.
- Doesn't fit into a pocket well at all.
LawDog